How to style a checkbox using CSS

I am trying to style a checkbox using the following:

<input type="checkbox" style="border:2px dotted #00f;display:block;background:#ff0000;" />

But the style is not applied. The checkbox still displays its default style. How do I give it the specified style?

UPDATE:

The below answer references the state of things before widespread availability of CSS 3. In modern browsers (including Internet Explorer 9 and later) it is more straightforward to create checkbox replacements with your preferred styling, without using JavaScript.

Here are some useful links:

• Creating Custom Form Checkboxes with Just CSS
• Easy CSS Checkbox Generator
• Stuff You Can Do With The Checkbox Hack
• Implementing Custom Checkboxes and Radio Buttons with CSS3
• How to Style a Checkbox With CSS

It is worth noting that the fundamental issue has not changed. You still can't apply styles (borders, etc.) directly to the checkbox element and have those styles affect the display of the HTML checkbox. What has changed, however, is that it's now possible to hide the actual checkbox and replace it with a styled element of your own, using nothing but CSS. In particular, because CSS now has a widely supported :checked selector, you can make your replacement correctly reflect the checked status of the box.

---

OLDER ANSWER

Here's a useful article about styling checkboxes. Basically, that writer found that it varies tremendously from browser to browser, and that many browsers always display the default checkbox no matter how you style it. So there really isn't an easy way.

It's not hard to imagine a workaround where you would use JavaScript to overlay an image on the checkbox and have clicks on that image cause the real checkbox to be checked. Users without JavaScript would see the default checkbox.

Edited to add: here's a nice script that does this for you; it hides the real checkbox element, replaces it with a styled span, and redirects the click events.

You can achieve quite a cool custom checkbox effect by using the new abilities that come with the :after and :before pseudo classes. The advantage to this, is: You don't need to add anything more to the DOM, just the standard checkbox.

Note this will only work for compatible browsers. I believe this is related to the fact that some browsers do not allow you to set :after and :before on input elements. Which unfortunately means for the moment only WebKit browsers are supported. Firefox + Internet Explorer will still allow the checkboxes to function, just unstyled, and this will hopefully change in the future (the code does not use vendor prefixes).

This is a WebKit browser solution only (Chrome, Safari, Mobile browsers)

See Example Fiddle

$(function() {
  $('input').change(function() {
    $('div').html(Math.random());
  });
});

/* Main Classes */
.myinput[type="checkbox"]:before {
  position: relative;
  display: block;
  width: 11px;
  height: 11px;
  border: 1px solid #808080;
  content: "";
  background: #FFF;
}

.myinput[type="checkbox"]:after {
  position: relative;
  display: block;
  left: 2px;
  top: -11px;
  width: 7px;
  height: 7px;
  border-width: 1px;
  border-style: solid;
  border-color: #B3B3B3 #dcddde #dcddde #B3B3B3;
  content: "";
  background-image: linear-gradient(135deg, #B1B6BE 0%, #FFF 100%);
  background-repeat: no-repeat;
  background-position: center;
}

.myinput[type="checkbox"]:checked:after {
  background-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAcAAAAHCAQAAABuW59YAAAACXBIWXMAAAsTAAALEwEAmpwYAAAAIGNIUk0AAHolAACAgwAA+f8AAIDpAAB1MAAA6mAAADqYAAAXb5JfxUYAAAB2SURBVHjaAGkAlv8A3QDyAP0A/QD+Dam3W+kCAAD8APYAAgTVZaZCGwwA5wr0AvcA+Dh+7UX/x24AqK3Wg/8nt6w4/5q71wAAVP9g/7rTXf9n/+9N+AAAtpJa/zf/S//DhP8H/wAA4gzWj2P4lsf0JP0A/wADAHB0Ngka6UmKAAAAAElFTkSuQmCC'), linear-gradient(135deg, #B1B6BE 0%, #FFF 100%);
}

.myinput[type="checkbox"]:disabled:after {
  -webkit-filter: opacity(0.4);
}

.myinput[type="checkbox"]:not(:disabled):checked:hover:after {
  background-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAcAAAAHCAQAAABuW59YAAAACXBIWXMAAAsTAAALEwEAmpwYAAAAIGNIUk0AAHolAACAgwAA+f8AAIDpAAB1MAAA6mAAADqYAAAXb5JfxUYAAAB2SURBVHjaAGkAlv8A3QDyAP0A/QD+Dam3W+kCAAD8APYAAgTVZaZCGwwA5wr0AvcA+Dh+7UX/x24AqK3Wg/8nt6w4/5q71wAAVP9g/7rTXf9n/+9N+AAAtpJa/zf/S//DhP8H/wAA4gzWj2P4lsf0JP0A/wADAHB0Ngka6UmKAAAAAElFTkSuQmCC'), linear-gradient(135deg, #8BB0C2 0%, #FFF 100%);
}

.myinput[type="checkbox"]:not(:disabled):hover:after {
  background-image: linear-gradient(135deg, #8BB0C2 0%, #FFF 100%);
  border-color: #85A9BB #92C2DA #92C2DA #85A9BB;
}

.myinput[type="checkbox"]:not(:disabled):hover:before {
  border-color: #3D7591;
}

/* Large checkboxes */
.myinput.large {
  height: 22px;
  width: 22px;
}

.myinput.large[type="checkbox"]:before {
  width: 20px;
  height: 20px;
}

.myinput.large[type="checkbox"]:after {
  top: -20px;
  width: 16px;
  height: 16px;
}

/* Custom checkbox */
.myinput.large.custom[type="checkbox"]:checked:after {
  background-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAAGHRFWHRBdXRob3IAbWluZWNyYWZ0aW5mby5jb23fZidLAAAAk0lEQVQ4y2P4//8/AyUYwcAD+OzN/oMwshjRBoA0Gr8+DcbIhhBlAEyz+qZZ/7WPryHNAGTNMOxpJvo/w0/uP0kGgGwGaZbrKgfTGnLc/0nyAgiDbEY2BCRGdCDCnA2yGeYVog0Aae5MV4c7Gzk6CRqAbDM2w/EaQEgzXgPQnU2SAcTYjNMAYm3GaQCxNuM0gFwMAPUKd8XyBVDcAAAAAElFTkSuQmCC'), linear-gradient(135deg, #B1B6BE 0%, #FFF 100%);
}

.myinput.large.custom[type="checkbox"]:not(:disabled):checked:hover:after {
  background-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAAGHRFWHRBdXRob3IAbWluZWNyYWZ0aW5mby5jb23fZidLAAAAk0lEQVQ4y2P4//8/AyUYwcAD+OzN/oMwshjRBoA0Gr8+DcbIhhBlAEyz+qZZ/7WPryHNAGTNMOxpJvo/w0/uP0kGgGwGaZbrKgfTGnLc/0nyAgiDbEY2BCRGdCDCnA2yGeYVog0Aae5MV4c7Gzk6CRqAbDM2w/EaQEgzXgPQnU2SAcTYjNMAYm3GaQCxNuM0gFwMAPUKd8XyBVDcAAAAAElFTkSuQmCC'), linear-gradient(135deg, #8BB0C2 0%, #FFF 100%);
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<table style="width:100%">
  <tr>
    <td>Normal:</td>
    <td><input type="checkbox" /></td>
    <td><input type="checkbox" checked="checked" /></td>
    <td><input type="checkbox" disabled="disabled" /></td>
    <td><input type="checkbox" disabled="disabled" checked="checked" /></td>
  </tr>
  <tr>
    <td>Small:</td>
    <td><input type="checkbox" class="myinput" /></td>
    <td><input type="checkbox" checked="checked" class="myinput" /></td>
    <td><input type="checkbox" disabled="disabled" class="myinput" /></td>
    <td><input type="checkbox" disabled="disabled" checked="checked" class="myinput" /></td>
  </tr>
  <tr>
    <td>Large:</td>
    <td><input type="checkbox" class="myinput large" /></td>
    <td><input type="checkbox" checked="checked" class="myinput large" /></td>
    <td><input type="checkbox" disabled="disabled" class="myinput large" /></td>
    <td><input type="checkbox" disabled="disabled" checked="checked" class="myinput large" /></td>
  </tr>
  <tr>
    <td>Custom icon:</td>
    <td><input type="checkbox" class="myinput large custom" /></td>
    <td><input type="checkbox" checked="checked" class="myinput large custom" /></td>
    <td><input type="checkbox" disabled="disabled" class="myinput large custom" /></td>
    <td><input type="checkbox" disabled="disabled" checked="checked" class="myinput large custom" /></td>
  </tr>
</table>

Bonus Webkit style flipswitch fiddle

$(function() {
  var f = function() {
    $(this).next().text($(this).is(':checked') ? ':checked' : ':not(:checked)');
  };
  $('input').change(f).trigger('change');
});

body {
  font-family: arial;
}

.flipswitch {
  position: relative;
  background: white;
  width: 120px;
  height: 40px;
  -webkit-appearance: initial;
  border-radius: 3px;
  -webkit-tap-highlight-color: rgba(0, 0, 0, 0);
  outline: none;
  font-size: 14px;
  font-family: Trebuchet, Arial, sans-serif;
  font-weight: bold;
  cursor: pointer;
  border: 1px solid #ddd;
}

.flipswitch:after {
  position: absolute;
  top: 5%;
  display: block;
  line-height: 32px;
  width: 45%;
  height: 90%;
  background: #fff;
  box-sizing: border-box;
  text-align: center;
  transition: all 0.3s ease-in 0s;
  color: black;
  border: #888 1px solid;
  border-radius: 3px;
}

.flipswitch:after {
  left: 2%;
  content: "OFF";
}

.flipswitch:checked:after {
  left: 53%;
  content: "ON";
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>

<h2>Webkit friendly mobile-style checkbox/flipswitch</h2>
<input type="checkbox" class="flipswitch" /> &nbsp;
<span></span>
<br>
<input type="checkbox" checked="checked" class="flipswitch" /> &nbsp;
<span></span>

Before you begin (as of Jan 2015)

The original question and answer are now ~5 years old. As such, this is a little bit of an update.

Firstly, there are a number of approaches when it comes to styling checkboxes. The basic tenet is:

1. You will need to hide the default checkbox control which is styled by your browser, and cannot be overridden in any meaningful way using CSS.

2. With the control hidden, you will still need to be able to detect and toggle its checked state.

3. The checked state of the checkbox will need to be reflected by styling a new element.

The solution (in principle)

The above can be accomplished by a number of means — and you will often hear that using CSS3 pseudo-elements is the right way. Actually, there is no real right or wrong way, it depends on the approach most suitable for the context you will be using it in. That said, I have a preferred one.

1. Wrap your checkbox in a label element. This will mean that even when it is hidden, you can still toggle its checked state by clicking anywhere within the label.

2. Hide your checkbox.

3. Add a new element after the checkbox which you will style accordingly. It must appear after the checkbox so it can be selected using CSS and styled dependent on the :checked state. CSS cannot select 'backwards'.

The solution (in code)

label input {
  visibility: hidden;/* <-- Hide the default checkbox. The rest is to hide and allow tabbing, which display:none prevents */
  display: block;
  height: 0;
  width: 0;
  position: absolute;
  overflow: hidden;
}
label span {/* <-- Style the artificial checkbox */
  height: 10px;
  width: 10px;
  border: 1px solid grey;
  display: inline-block;
}
[type=checkbox]:checked + span {/* <-- Style its checked state */
  background: black;
}

<label>
  <input type='checkbox'>
  <span></span>
  Checkbox label text
</label>

Refinement (using icons)

"But hey!" I hear you shout. What about if I want to show a nice little tick or cross in the box? And I don't want to use background images!

Well, this is where CSS3's pseudo-elements can come into play. These support the content property which allows you to inject Unicode icons representing either state. Alternatively, you could use a third party font icon source such as font awesome (though make sure you also set the relevant font-family, e.g. to FontAwesome)

label input {
  display: none; /* Hide the default checkbox */
}

/* Style the artificial checkbox */
label span {
  height: 10px;
  width: 10px;
  border: 1px solid grey;
  display: inline-block;
  position: relative;
}

/* Style its checked state...with a ticked icon */
[type=checkbox]:checked + span:before {
  content: '\2714';
  position: absolute;
  top: -5px;
  left: 0;
}

<label>
  <input type='checkbox'>
  <span></span>
  Checkbox label text
</label>

There is a way to do this using just CSS. We can (ab)use the label element and style that element instead. The caveat is that this will not work for Internet Explorer 8 and lower versions.

.myCheckbox input {
  position: relative;
  z-index: -9999;
}

.myCheckbox span {
  width: 20px;
  height: 20px;
  display: block;
  background: url("link_to_image");
}

.myCheckbox input:checked + span {
  background: url("link_to_another_image");
}

<label for="test">Label for my styled "checkbox"</label>
<label class="myCheckbox">
  <input type="checkbox" name="test" />
  <span></span>
</label>

I always use pseudo elements :before and :after for changing the appearance of checkboxes and radio buttons. it's works like a charm.

Refer this link for more info

CODEPEN

Steps

1. Hide the default checkbox using css rules like visibility:hidden or opacity:0 or position:absolute;left:-9999px etc.
2. Create a fake checkbox using :before element and pass either an empty or a non-breaking space '\00a0';
3. When the checkbox is in :checked state, pass the unicode content: "\2713", which is a checkmark;
4. Add :focus style to make the checkbox accessible.
5. Done

Here is how I did it.

.box {
  background: #666666;
  color: #ffffff;
  width: 250px;
  padding: 10px;
  margin: 1em auto;
}
p {
  margin: 1.5em 0;
  padding: 0;
}
input[type="checkbox"] {
  visibility: hidden;
}
label {
  cursor: pointer;
}
input[type="checkbox"] + label:before {
  border: 1px solid #333;
  content: "\00a0";
  display: inline-block;
  font: 16px/1em sans-serif;
  height: 16px;
  margin: 0 .25em 0 0;
  padding: 0;
  vertical-align: top;
  width: 16px;
}
input[type="checkbox"]:checked + label:before {
  background: #fff;
  color: #333;
  content: "\2713";
  text-align: center;
}
input[type="checkbox"]:checked + label:after {
  font-weight: bold;
}

input[type="checkbox"]:focus + label::before {
    outline: rgb(59, 153, 252) auto 5px;
}

<div class="content">
  <div class="box">
    <p>
      <input type="checkbox" id="c1" name="cb">
      <label for="c1">Option 01</label>
    </p>
    <p>
      <input type="checkbox" id="c2" name="cb">
      <label for="c2">Option 02</label>
    </p>
    <p>
      <input type="checkbox" id="c3" name="cb">
      <label for="c3">Option 03</label>
    </p>
  </div>
</div>

Much more stylish using :before and :after

body{
  font-family: sans-serif;  
}

.container {
    margin-top: 50px;
    margin-left: 20px;
    margin-right: 20px;
}
.checkbox {
    width: 100%;
    margin: 15px auto;
    position: relative;
    display: block;
}

.checkbox input[type="checkbox"] {
    width: auto;
    opacity: 0.00000001;
    position: absolute;
    left: 0;
    margin-left: -20px;
}
.checkbox label {
    position: relative;
}
.checkbox label:before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    margin: 4px;
    width: 22px;
    height: 22px;
    transition: transform 0.28s ease;
    border-radius: 3px;
    border: 2px solid #7bbe72;
}
.checkbox label:after {
  content: '';
    display: block;
    width: 10px;
    height: 5px;
    border-bottom: 2px solid #7bbe72;
    border-left: 2px solid #7bbe72;
    -webkit-transform: rotate(-45deg) scale(0);
    transform: rotate(-45deg) scale(0);
    transition: transform ease 0.25s;
    will-change: transform;
    position: absolute;
    top: 12px;
    left: 10px;
}
.checkbox input[type="checkbox"]:checked ~ label::before {
    color: #7bbe72;
}

.checkbox input[type="checkbox"]:checked ~ label::after {
    -webkit-transform: rotate(-45deg) scale(1);
    transform: rotate(-45deg) scale(1);
}

.checkbox label {
    min-height: 34px;
    display: block;
    padding-left: 40px;
    margin-bottom: 0;
    font-weight: normal;
    cursor: pointer;
    vertical-align: sub;
}
.checkbox label span {
    position: absolute;
    top: 50%;
    -webkit-transform: translateY(-50%);
    transform: translateY(-50%);
}
.checkbox input[type="checkbox"]:focus + label::before {
    outline: 0;
}

<div class="container"> 
  <div class="checkbox">
     <input type="checkbox" id="checkbox" name="" value="">
     <label for="checkbox"><span>Checkbox</span></label>
  </div>

  <div class="checkbox">
     <input type="checkbox" id="checkbox2" name="" value="">
     <label for="checkbox2"><span>Checkbox</span></label>
  </div>
</div>

I'd follow the advice of SW4's answer. Not anymore: Volomike's answer is far superior to all the answers here (note my suggested improvement in the comment to the answer). Proceed reading this answer if you are curious about alternative approaches, which this answer comments.

---

First of all, hide the checkbox and to cover it with a custom span, suggesting this HTML:

<label>
  <input type="checkbox">
  <span>send newsletter</span>
</label>

The wrap in label neatly allows clicking the text without the need of "for-id" attribute linking. However,

Do not hide it using visibility: hidden or display: none

It works by clicking or tapping, but that is a lame way to use checkboxes. Some people still use much more effective Tab to move focus, Space to activate, and hiding with that method disables it. If the form is long, one will save someone's wrists to use tabindex or accesskey attributes. And if you observe the system checkbox behavior, there is a decent shadow on hover. The well styled checkbox should follow this behavior.

cobberboy's answer recommends Font Awesome which is usually better than bitmap since fonts are scalable vectors. Working with the HTML above, I'd suggest these CSS rules:

1. Hide checkboxes

    input[type="checkbox"] {
      position: absolute;
      opacity: 0;
      z-index: -1;
    }
   

   I use just negative z-index since my example uses big enough checkbox skin to cover it fully. I don't recommend left: -999px since it is not reusable in every layout. Bushan wagh's answer provides a bulletproof way to hide it and convince the browser to use tabindex, so it is a good alternative. Anyway, both is just a hack. The proper way today is appearance: none, see Joost's answer:

    input[type="checkbox"] {
      appearance: none;
      -webkit-appearance: none;
      -moz-appearance: none;
    }
   

2. Style checkbox label

    input[type="checkbox"] + span {
      font: 16pt sans-serif;
      color: #000;
    }
   

3. Add checkbox skin

    input[type="checkbox"] + span:before {
      font: 16pt FontAwesome;
      content: '\00f096';
      display: inline-block;
      width: 16pt;
      padding: 2px 0 0 3px;
      margin-right: 0.5em;
    }
   

\00f096 is Font Awesome's square-o, padding is adjusted to provide even dotted outline on focus (see below).

4. Add checkbox checked skin

    input[type="checkbox"]:checked + span:before {
      content: '\00f046';
    }
   

\00f046 is Font Awesome's check-square-o, which is not the same width as square-o, which is the reason for the width style above.

5. Add focus outline

    input[type="checkbox"]:focus + span:before {
      outline: 1px dotted #aaa;
    }
   

   Safari doesn't provide this feature (see @Jason Sankey's comment), see this answer for Safari-only CSS

6. Set gray color for disabled checkbox

    input[type="checkbox"]:disabled + span {
      color: #999;
    }
   

7. Set hover shadow on non-disabled checkbox

    input[type="checkbox"]:not(:disabled) + span:hover:before {
      text-shadow: 0 1px 2px #77F;
    }
   

---

Test it on JS Fiddle

Try to hover the mouse over the checkboxes and use Tab and Shift+Tab to move and Space to toggle.

2022 accessible solution - use accent-color

2022 UPDATE: use the new accent-color property and make certain to meet a proper contrast ratio of 3:1 to ensure accessibility. This also works for radio buttons.

.red-input {
    accent-color: #9d3039;
    height: 20px; /* not needed */
    width: 20px; /* not needed */
}

<input class="red-input" type="checkbox" />

<!-- Radio button example -->
<input class="red-input" type="radio" />

---

Old answer:

I have been scrolling and scrolling and tons of these answers simply throw accessibility out the door and violate WCAG in more than one way. I threw in radio buttons since most of the time when you're using custom checkboxes you want custom radio buttons too.

Fiddles:

• Checkboxes - pure CSS - free from 3rd party libraries
• Radio buttons - pure CSS - free from 3rd party libraries
• Checkboxes* that use FontAwesome but could be swapped with Glyphicons, etc. easily

Late to the party but somehow this is still difficult in 2019, 2020, 2021 so I have added my three solutions which are accessible and easy to drop in.

These are all JavaScript free, accessible, and external library free*...

If you want to plug-n-play with any of these just copy the style sheet from the fiddles, edit the color codes in the CSS to fit your needs, and be on your way. You can add a custom svg checkmark icon if you want for the checkboxes. I've added lots of comments for those non-CSS'y folks.

If you have long text or a small container and are encountering text wrapping underneath the checkbox or radio button input then just convert to divs like this.

Longer explanation: I needed a solution that does not violate WCAG, doesn't rely on JavaScript or external libraries, and that does not break keyboard navigation like tabbing or spacebar to select, that allows focus events, a solution that allows for disabled checkboxes that are both checked and unchecked, and finally a solution where I can customize the look of the checkbox however I want with different background-color's, border-radius, svg backgrounds, etc.

I used some combination of this answer from @Jan Turoň to come up with my own solution which seems to work quite well. I've done a radio button fiddle that uses a lot of the same code from the checkboxes in order to make this work with radio buttons too.

I am still learning accessibility so if I missed something please drop a comment and I will try to correct it.

Here is a code example of my checkboxes:

input[type="checkbox"] {
  position: absolute;
  opacity: 0;
  z-index: -1;
}

/* Text color for the label */
input[type="checkbox"]+span {
  cursor: pointer;
  font: 16px sans-serif;
  color: black;
}

/* Checkbox un-checked style */
input[type="checkbox"]+span:before {
  content: '';
  border: 1px solid grey;
  border-radius: 3px;
  display: inline-block;
  width: 16px;
  height: 16px;
  margin-right: 0.5em;
  margin-top: 0.5em;
  vertical-align: -2px;
}

/* Checked checkbox style (in this case the background is green #e7ffba, change this to change the color) */
input[type="checkbox"]:checked+span:before {
  /* NOTE: Replace the url with a path to an SVG of a checkmark to get a checkmark icon */
  background-image: url('https://cdnjs.cloudflare.com/ajax/libs/ionicons/4.5.6/collection/build/ionicons/svg/ios-checkmark.svg');
  background-repeat: no-repeat;
  background-position: center;
  /* The size of the checkmark icon, you may/may not need this */
  background-size: 25px;
  border-radius: 2px;
  background-color: #e7ffba;
  color: white;
}

/* Adding a dotted border around the active tabbed-into checkbox */
input[type="checkbox"]:focus+span:before,
input[type="checkbox"]:not(:disabled)+span:hover:before {
  /* Visible in the full-color space */
  box-shadow: 0px 0px 0px 2px rgba(0, 150, 255, 1);

  /* Visible in Windows high-contrast themes
     box-shadow will be hidden in these modes and
     transparency will not be hidden in high-contrast
     thus box-shadow will not show but the outline will
     providing accessibility */
  outline-color: transparent; /*switch to transparent*/
  outline-width: 2px;
  outline-style: dotted;
  }


/* Disabled checkbox styles */
input[type="checkbox"]:disabled+span {
  cursor: default;
  color: black;
  opacity: 0.5;
}

/* Styles specific to this fiddle that you do not need */
body {
  padding: 1em;
}
h1 {
  font-size: 18px;
}

<h1>
  NOTE: Replace the url for the background-image in CSS with a path to an SVG in your solution or CDN. This one was found from a quick google search for a checkmark icon cdn
</h1>

<p>You can easily change the background color, checkbox symbol, border-radius, etc.</p>

<label>
  <input type="checkbox">
  <span>Try using tab and space</span>
</label>

<br>

<label>
  <input type="checkbox" checked disabled>
  <span>Disabled Checked Checkbox</span>
</label>

<br>

<label>
  <input type="checkbox" disabled>
  <span>Disabled Checkbox</span>
</label>
<br>

<label>
  <input type="checkbox">
  <span>Normal Checkbox</span>
</label>

<br>

<label>
  <input type="checkbox">
  <span>Another Normal Checkbox</span>
</label>

With pure CSS, nothing fancy with :before and :after, no transforms, you can turn off the default appearance and then style it with an inline background image like the following example. This works in Chrome, Firefox, Safari, and now Edge (Chromium Edge).

INPUT[type=checkbox]:focus
{
    outline: 1px solid rgba(0, 0, 0, 0.2);
}

INPUT[type=checkbox]
{
    background-color: #DDD;
    border-radius: 2px;
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    width: 17px;
    height: 17px;
    cursor: pointer;
    position: relative;
    top: 5px;
}

INPUT[type=checkbox]:checked
{
    background-color: #409fd6;
    background: #409fd6 url("data:image/gif;base64,R0lGODlhCwAKAIABAP////3cnSH5BAEKAAEALAAAAAALAAoAAAIUjH+AC73WHIsw0UCjglraO20PNhYAOw==") 3px 3px no-repeat;
}

<form>
  <label><input type="checkbox"> I Agree To Terms &amp; Conditions</label>
</form>

Simple to implement and easily customizable solution

After a lot of search and testing I got this solution which is simple to implement and easier to customize. In this solution:

1. You don't need external libraries and files
2. You don't need to add extra HTML in your page
3. You don't need to change checkbox names and id

Simple put the flowing CSS at the top of your page and all checkboxes style will change like this:

input[type=checkbox] {
  transform: scale(1.5);
}

input[type=checkbox] {
  width: 30px;
  height: 30px;
  margin-right: 8px;
  cursor: pointer;
  font-size: 17px;
  visibility: hidden;
}

input[type=checkbox]:after,
input[type=checkbox]::after {
  content: " ";
  background-color: #fff;
  display: inline-block;
  margin-left: 10px;
  padding-bottom: 5px;
  color: #00BFF0;
  width: 22px;
  height: 25px;
  visibility: visible;
  border: 1px solid #00BFF0;
  padding-left: 3px;
  border-radius: 5px;
}

input[type=checkbox]:checked:after,
input[type=checkbox]:checked::after {
  content: "\2714";
  padding: -5px;
  font-weight: bold;
}

<input type="checkbox" id="checkbox1" />
<label for="checkbox1">Checkbox</label>

The CSS Basic User Interface Module Level 4 adds support for this (finally) via a new solution called accent-color, and it's actually quite simple, unlike pretty much every other answer here:

input {
    accent-color: rebeccapurple;
}

<input type="checkbox" />

Simply set whatever CSS color (e.g. named value, hex code, etc.) you want in as the value of accent-color, and it will be applied.

This currently works in Chrome (v93+), Edge (v93+), Firefox (v92+), Opera (v79+), and Safari (v15.4+).

Note: Edge, Chrome, and Opera (and possibly Safari; I can't test that) currently don't support alpha channel values via rgba() either (the RGB values of rgba() will still "work"; the alpha channel will simply be ignored by the browser). See MDN Browser Support for more information.

You can style checkboxes with a little trickery using the label element an example is below:

.checkbox > input[type=checkbox] {
  visibility: hidden;
}

.checkbox {
  position: relative;
  display: block;
  width: 80px;
  height: 26px;
  margin: 0 auto;
  background: #FFF;
  border: 1px solid #2E2E2E;
  border-radius: 2px;
  -webkit-border-radius: 2px;
  -moz-border-radius: 2px;
}

.checkbox:after {
  position: absolute;
  display: inline;
  right: 10px;
  content: 'no';
  color: #E53935;
  font: 12px/26px Arial, sans-serif;
  font-weight: bold;
  text-transform: capitalize;
  z-index: 0;
}

.checkbox:before {
  position: absolute;
  display: inline;
  left: 10px;
  content: 'yes';
  color: #43A047;
  font: 12px/26px Arial, sans-serif;
  font-weight: bold;
  text-transform: capitalize;
  z-index: 0;
}

.checkbox label {
  position: absolute;
  display: block;
  top: 3px;
  left: 3px;
  width: 34px;
  height: 20px;
  background: #2E2E2E;
  cursor: pointer;
  transition: all 0.5s linear;
  -webkit-transition: all 0.5s linear;
  -moz-transition: all 0.5s linear;
  border-radius: 2px;
  -webkit-border-radius: 2px;
  -moz-border-radius: 2px;
  z-index: 1;
}

.checkbox input[type=checkbox]:checked + label {
  left: 43px;
}

<div class="checkbox">
  <input id="checkbox1" type="checkbox" value="1" />
  <label for="checkbox1"></label>
</div>

And a FIDDLE for the above code. Note that some CSS doesn't work in older versions of browsers, but I'm sure there are some fancy JavaScript examples out there!

You can avoid adding extra markup. This works everywhere except IE for Desktop (but works in IE for Windows Phone and Microsoft Edge) via setting CSS appearance:

input[type="checkbox"] {
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;

  /* Styling checkbox */
  width: 16px;
  height: 16px;
  background-color: red;
}

input[type="checkbox"]:checked {
  background-color: green;
}

<input type="checkbox" />

Recently I found a quite interesting solution to the problem.

You could use appearance: none; to turn off the checkbox's default style and then write your own over it like described here (Example 4).

input[type=checkbox] {
  width: 23px;
  height: 23px;
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
  margin-right: 10px;
  background-color: #878787;
  outline: 0;
  border: 0;
  display: inline-block;
  -webkit-box-shadow: none !important;
  -moz-box-shadow: none !important;
  box-shadow: none !important;
}

input[type=checkbox]:focus {
  outline: none;
  border: none !important;
  -webkit-box-shadow: none !important;
  -moz-box-shadow: none !important;
  box-shadow: none !important;
}

input[type=checkbox]:checked {
  background-color: green;
  text-align: center;
  line-height: 15px;
}

<input type="checkbox">

Unfortunately browser support is quite bad for the appearance option. From my personal testing I only got Opera and Chrome working correctly. But this would be the way to go to keep it simple when better support comes or you only want to use Chrome/Opera.

Example JSFiddle

"Can I use?" link

I prefer to use icon fonts (such as FontAwesome) since it's easy to modify their colours with CSS, and they scale really well on high pixel-density devices. So here's another pure CSS variant, using similar techniques to those above.

(Below is a static image so you can visualize the result; see the JSFiddle for an interactive version.)

As with other solutions, it uses the label element. An adjacent span holds our checkbox character.

span.bigcheck-target {
  font-family: FontAwesome; /* Use an icon font for the checkbox */
}

input[type='checkbox'].bigcheck {
  position: relative;
  left: -999em; /* Hide the real checkbox */
}

input[type='checkbox'].bigcheck + span.bigcheck-target:after {
  content: "\f096"; /* In fontawesome, is an open square (fa-square-o) */
}

input[type='checkbox'].bigcheck:checked + span.bigcheck-target:after {
  content: "\f046"; /* fontawesome checked box (fa-check-square-o) */
}

/* ==== Optional - colors and padding to make it look nice === */
body {
  background-color: #2C3E50;
  color: #D35400;
  font-family: sans-serif;
  font-weight: 500;
  font-size: 4em; /* Set this to whatever size you want */
}

span.bigcheck {
  display: block;
  padding: 0.5em;
}

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css" />

<span class="bigcheck">
  <label class="bigcheck">
    Cheese
    <input type="checkbox" class="bigcheck" name="cheese" value="yes" />
    <span class="bigcheck-target"></span>
  </label>
</span>

Here's the JSFiddle for it.

My solution

input[type="checkbox"] {
  cursor: pointer;
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
  outline: 0;
  background: lightgray;
  height: 16px;
  width: 16px;
  border: 1px solid white;
}

input[type="checkbox"]:checked {
  background: #2aa1c0;
}

input[type="checkbox"]:hover {
  filter: brightness(90%);
}

input[type="checkbox"]:disabled {
  background: #e6e6e6;
  opacity: 0.6;
  pointer-events: none;
}

input[type="checkbox"]:after {
  content: '';
  position: relative;
  left: 40%;
  top: 20%;
  width: 15%;
  height: 40%;
  border: solid #fff;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
  display: none;
}

input[type="checkbox"]:checked:after {
  display: block;
}

input[type="checkbox"]:disabled:after {
  border-color: #7b7b7b;
}

<input type="checkbox"><br>
<input type="checkbox" checked><br>
<input type="checkbox" disabled><br>
<input type="checkbox" disabled checked><br>

You can simply use appearance: none on modern browsers, so that there is no default styling and all your styles are applied properly:

input[type=checkbox] {
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
  display: inline-block;
  width: 2em;
  height: 2em;
  border: 1px solid gray;
  outline: none;
  vertical-align: middle;
}

input[type=checkbox]:checked {
  background-color: blue;
}

Here is a simple CSS solution without any jQuery or JavaScript code.

I am using FontAwseome icons but you can use any image

input[type=checkbox] {
  display: inline-block;
  font-family: FontAwesome;
  font-style: normal;
  font-weight: normal;
  line-height: 1;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  visibility: hidden;
  font-size: 14px;
}

input[type=checkbox]:before {
  content: @fa-var-square-o;
  visibility: visible;
  /*font-size: 12px;*/
}

input[type=checkbox]:checked:before {
  content: @fa-var-check-square-o;
}

From my googling, this is the easiest way for checkbox styling. Just add :after and :checked:after CSS based on your design.

body{
  background: #DDD;
}
span{
  margin-left: 30px;
}
input[type=checkbox] {
    cursor: pointer;
    font-size: 17px;
    visibility: hidden;
    position: absolute;
    top: 0;
    left: 0;
    transform: scale(1.5);
}

input[type=checkbox]:after {
    content: " ";
    background-color: #fff;
    display: inline-block;
    color: #00BFF0;
    width: 14px;
    height: 19px;
    visibility: visible;
    border: 1px solid #FFF;
    padding: 0 3px;
    margin: 2px 0;
    border-radius: 8px;
    box-shadow: 0 0 15px 0 rgba(0,0,0,0.08), 0 0 2px 0 rgba(0,0,0,0.16);
}

input[type=checkbox]:checked:after {
    content: "\2714";
    display: unset;
    font-weight: bold;
}

<input type="checkbox"> <span>Select Text</span>

Yikes! All these workarounds have led me to the conclusion that the HTML checkbox kind of sucks if you want to style it.

As a forewarning, this isn't a CSS implementation. I just thought I'd share the workaround I came up with in case anyone else might find it useful.

---

I used the HTML5 canvas element.

The upside to this is that you don't have to use external images and can probably save some bandwidth.

The downside is that if a browser for some reason can't render it correctly, then there's no fallback. Though whether this remains an issue in 2017 is debatable.

Update

I found the old code quite ugly, so I decided to give it a rewrite.

Object.prototype.create = function(args){
    var retobj = Object.create(this);

    retobj.constructor(args || null);

    return retobj;
}

var Checkbox = Object.seal({
    width: 0,
    height: 0,
    state: 0,
    document: null,
    parent: null,
    canvas: null,
    ctx: null,

    /*
     * args:
     * name      default             desc.
     *
     * width     15                  width
     * height    15                  height
     * document  window.document     explicit document reference
     * target    this.document.body  target element to insert checkbox into
     */
    constructor: function(args){
        if(args === null)
            args = {};

        this.width = args.width || 15;
        this.height = args.height || 15;
        this.document = args.document || window.document;
        this.parent = args.target || this.document.body;
        this.canvas = this.document.createElement("canvas");
        this.ctx = this.canvas.getContext('2d');

        this.canvas.width = this.width;
        this.canvas.height = this.height;
        this.canvas.addEventListener("click", this.ev_click(this), false);
        this.parent.appendChild(this.canvas);
        this.draw();
    },

    ev_click: function(self){
        return function(unused){
            self.state = !self.state;
            self.draw();
        }
    },

    draw_rect: function(color, offset){
        this.ctx.fillStyle = color;
        this.ctx.fillRect(offset, offset,
                this.width - offset * 2, this.height - offset * 2);
    },

    draw: function(){
        this.draw_rect("#CCCCCC", 0);
        this.draw_rect("#FFFFFF", 1);

        if(this.is_checked())
            this.draw_rect("#000000", 2);
    },

    is_checked: function(){
        return !!this.state;
    }
});

Here's a working demo.

The new version uses prototypes and differential inheritance to create an efficient system for creating checkboxes. To create a checkbox:

var my_checkbox = Checkbox.create();

This will immediately add the checkbox to the DOM and hook up the events. To query whether a checkbox is checked:

my_checkbox.is_checked(); // True if checked, else false

Also important to note is that I got rid of the loop.

Update 2

Something I neglected to mention in the last update is that using the canvas has more advantages than just making a checkbox that looks however you want it to look. You could also create multi-state checkboxes, if you wanted to.

Object.prototype.create = function(args){
    var retobj = Object.create(this);

    retobj.constructor(args || null);

    return retobj;
}

Object.prototype.extend = function(newobj){
    var oldobj = Object.create(this);

    for(prop in newobj)
        oldobj[prop] = newobj[prop];

    return Object.seal(oldobj);
}

var Checkbox = Object.seal({
    width: 0,
    height: 0,
    state: 0,
    document: null,
    parent: null,
    canvas: null,
    ctx: null,

    /*
     * args:
     * name      default             desc.
     *
     * width     15                  width
     * height    15                  height
     * document  window.document     explicit document reference
     * target    this.document.body  target element to insert checkbox into
     */
    constructor: function(args){
        if(args === null)
            args = {};

        this.width = args.width || 15;
        this.height = args.height || 15;
        this.document = args.document || window.document;
        this.parent = args.target || this.document.body;
        this.canvas = this.document.createElement("canvas");
        this.ctx = this.canvas.getContext('2d');

        this.canvas.width = this.width;
        this.canvas.height = this.height;
        this.canvas.addEventListener("click", this.ev_click(this), false);
        this.parent.appendChild(this.canvas);
        this.draw();
    },

    ev_click: function(self){
        return function(unused){
            self.state = !self.state;
            self.draw();
        }
    },

    draw_rect: function(color, offsetx, offsety){
        this.ctx.fillStyle = color;
        this.ctx.fillRect(offsetx, offsety,
                this.width - offsetx * 2, this.height - offsety * 2);
    },

    draw: function(){
        this.draw_rect("#CCCCCC", 0, 0);
        this.draw_rect("#FFFFFF", 1, 1);
        this.draw_state();
    },

    draw_state: function(){
        if(this.is_checked())
            this.draw_rect("#000000", 2, 2);
    },

    is_checked: function(){
        return this.state == 1;
    }
});

var Checkbox3 = Checkbox.extend({
    ev_click: function(self){
        return function(unused){
            self.state = (self.state + 1) % 3;
            self.draw();
        }
    },

    draw_state: function(){
        if(this.is_checked())
            this.draw_rect("#000000", 2, 2);

        if(this.is_partial())
            this.draw_rect("#000000", 2, (this.height - 2) / 2);
    },

    is_partial: function(){
        return this.state == 2;
    }
});

I modified slightly the Checkbox used in the last snippet so that it is more generic, making it possible to "extend" it with a checkbox that has 3 states. Here's a demo. As you can see, it already has more functionality than the built-in checkbox.

Something to consider when you're choosing between JavaScript and CSS.

Old, poorly-designed code

Working Demo

First, set up a canvas

var canvas = document.createElement('canvas'),
    ctx = canvas.getContext('2d'),
    checked = 0; // The state of the checkbox
canvas.width = canvas.height = 15; // Set the width and height of the canvas
document.body.appendChild(canvas);
document.body.appendChild(document.createTextNode(' Togglable Option'));

Next, devise a way to have the canvas update itself.

(function loop(){
  // Draws a border
  ctx.fillStyle = '#ccc';
  ctx.fillRect(0,0,15,15);
  ctx.fillStyle = '#fff';
  ctx.fillRect(1, 1, 13, 13);
  // Fills in canvas if checked
  if(checked){
    ctx.fillStyle = '#000';
    ctx.fillRect(2, 2, 11, 11);
  }
  setTimeout(loop, 1000/10); // Refresh 10 times per second
})();

The last part is to make it interactive. Luckily, it's pretty simple:

canvas.onclick = function(){
  checked = !checked;
}

This is where you might have problems in IE, due to their weird event handling model in JavaScript.

---

I hope this helps someone; it definitely suited my needs.

Modify the checkbox style with plain CSS. This does not require any JavaScript or HTML manipulation:

.form input[type="checkbox"]:before {
  display: inline-block;
  font: normal normal normal 14px/1 FontAwesome;
  font-size: inherit;
  text-rendering: auto;
  -webkit-font-smoothing: antialiased;
  content: "\f096";
  opacity: 1 !important;
  margin-top: -25px;
  appearance: none;
  background: #fff;
}

.form input[type="checkbox"]:checked:before {
  content: "\f046";
}

.form input[type="checkbox"] {
  font-size: 22px;
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
}

<link href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css" rel="stylesheet" />

<form class="form">
  <input type="checkbox" />
</form>

SCSS / SASS Implementation

A more modern approach

For those using SCSS (or easily converted to SASS), the following will be helpful. Effectively, make an element next to the checkbox, which is the one that you will style. When the checkbox is clicked, the CSS restyles the sister element (to your new, checked style). Code is below:

label.checkbox {
  input[type="checkbox"] {
    visibility: hidden;
    display: block;
    height: 0;
    width: 0;
    position: absolute;
    overflow: hidden;

    &:checked + span {
      background: $accent;
    }
  }

  span {
    cursor: pointer;
    height: 15px;
    width: 15px;
    border: 1px solid $accent;
    border-radius: 2px;
    display: inline-block;
    transition: all 0.2s $interpol;
  }
}

<label class="checkbox">
    <input type="checkbox" />
    <span></span>
    Label text
</label>

I think the easiest way to do it is by styling a label and making the checkbox invisible.

HTML

<input type="checkbox" id="first" />
<label for="first">&nbsp;</label>

CSS

checkbox {
  display: none;
}

checkbox + label {
  /* Style for checkbox normal */
  width: 16px;
  height: 16px;
}

checkbox::checked + label,
label.checked {
  /* Style for checkbox checked */
}

The checkbox, even though it is hidden, will still be accessible, and its value will be sent when a form is submitted. For old browsers you might have to change the class of the label to checked using JavaScript because I don't think old versions of Internet Explorer understand ::checked on the checkbox.

A simple and lightweight template as well:

input[type=checkbox] {
  cursor: pointer;
}

input[type=checkbox]:checked:before {
  content: "\2713";
  background: #fffed5;
  text-shadow: 1px 1px 1px rgba(0, 0, 0, .2);
  font-size: 20px;
  text-align: center;
  line-height: 8px;
  display: inline-block;
  width: 13px;
  height: 15px;
  color: #00904f;
  border: 1px solid #cdcdcd;
  border-radius: 4px;
  margin: -3px -3px;
  text-indent: 1px;
}

input[type=checkbox]:before {
  content: "\202A";
  background: #ffffff;
  text-shadow: 1px 1px 1px rgba(0, 0, 0, .2);
  font-size: 20px;
  text-align: center;
  line-height: 8px;
  display: inline-block;
  width: 13px;
  height: 15px;
  color: #00904f;
  border: 1px solid #cdcdcd;
  border-radius: 4px;
  margin: -3px -3px;
  text-indent: 1px;
}

<input type="checkbox" checked="checked">checked1<br>
<input type="checkbox">unchecked2<br>
<input type="checkbox" checked="checked" id="id1">
<label for="id1">checked2+label</label><br>
<label for="id2">unchecked2+label+rtl</label>
<input type="checkbox" id="id2">
<br>

https://jsfiddle.net/rvgccn5b/

No JavaScript or jQuery required.

Change your checkbox style simple way.

input[type="checkbox"] {
  display: none;
  border: none !important;
  box-shadow: none !important;
}

input[type="checkbox"] + label span {
  background: url(http://imgh.us/uncheck.png);
  width: 49px;
  height: 49px;
  display: inline-block;
  vertical-align: middle;
}

input[type="checkbox"]:checked + label span {
  background: url(http://imgh.us/check_2.png);
  width: 49px;
  height: 49px;
  vertical-align: middle;
}

<input type="checkbox" id="option" />
<label for="option"> <span></span> Click me </label>

Here is a JSFiddle link

Custom checkbox with CSS (WebKit browser solution only Chrome, Safari, Mobile browsers)

<input type="checkbox" id="cardAccptance" name="cardAccptance" value="Yes">
<label for="cardAccptance" class="bold"> Save Card for Future Use</label>

CSS:

    /* The checkbox-cu */
    
    .checkbox-cu {
        display: block;
        position: relative;
        padding-left: 35px;
        margin-bottom: 0;
        cursor: pointer;
        font-size: 16px;
        -webkit-user-select: none;
        -moz-user-select: none;
        -ms-user-select: none;
        user-select: none;
    }
    
    
    /* Hide the browser's default checkbox-cu */
    
    .checkbox-cu input {
        position: absolute;
        opacity: 0;
        cursor: pointer;
        height: 0;
        width: 0;
    }
    
    
    /* Create a custom checkbox-cu */
    
    .checkmark {
        position: absolute;
        top: 4px;
        left: 0;
        height: 20px;
        width: 20px;
        background-color: #eee;
        border: 1px solid #999;
        border-radius: 0;
        box-shadow: none;
    }
    
    
    /* On mouse-over, add a grey background color */
    
    .checkbox-cu:hover input~.checkmark {
        background-color: #ccc;
    }
    
    
    /* When the checkbox-cu is checked, add a blue background */
    
    .checkbox-cu input:checked~.checkmark {
        background-color: transparent;
    }
    
    
    /* Create the checkmark/indicator (hidden when not checked) */
    
    .checkmark:after {
        content: "";
        position: absolute;
        display: none;
    }
    
    
    /* Show the checkmark when checked */
    
    .checkbox-cu input:checked~.checkmark:after {
        display: block;
    }
    
    
    /* Style the checkmark/indicator */
    
    .checkbox-cu .checkmark::after {
        left: 7px;
        top: 3px;
        width: 6px;
        height: 9px;
        border: solid #28a745;
        border-width: 0 2px 2px 0;
        -webkit-transform: rotate(45deg);
        -ms-transform: rotate(45deg);
        transform: rotate(45deg);
        z-index: 100;
    }

By using Materialize with a custom stylesheet, you can achieve something like this:

CSS code

.custom_checkbox[type="checkbox"]:checked + span:not(.lever)::before {
  border: 2px solid transparent;
  border-bottom: 2px solid #ffd600;
  border-right: 2px solid #ffd600;
  background: transparent;
}

HTML code

<label>
    <input type="checkbox" class="custom_checkbox" />
    <span>Text</span>
</label>

Demo

JSFiddle demo

Here is a CSS/HTML-only version, no jQuery or JavaScript needed at all, Simple and clean HTML and really simple and short CSS.

Here is the JSFiddle

http://jsfiddle.net/v71kn3pr/

Here is the HTML:

<div id="myContainer">
    <input type="checkbox" name="myCheckbox" id="myCheckbox_01_item" value="red" />
    <label for="myCheckbox_01_item" class="box"></label>
    <label for="myCheckbox_01_item" class="text">I accept the Terms of Use.</label>
</div>

Here is the CSS

#myContainer {
    outline: black dashed 1px;
    width: 200px;
}
#myContainer input[type="checkbox"][name="myCheckbox"] {
    display: none;
}
#myContainer input[type="checkbox"][name="myCheckbox"]:not(:checked) + label.box {
    display: inline-block;
    width: 25px;
    height: 25px;
    border: black solid 1px;
    background: #FFF ;
    margin: 5px 5px;
}
#myContainer input[type="checkbox"][name="myCheckbox"]:checked + label.box {
    display: inline-block;
    width: 25px;
    height: 25px;
    border: black solid 1px;
    background: #F00;
    margin: 5px 5px;
}
#myContainer input[type="checkbox"][name="myCheckbox"] + label + label.text {
    font: normal 12px arial;
    display: inline-block;
    line-height: 27px;
    vertical-align: top;
    margin: 5px 0px;
}

This can be adapted to be able to have individual radio or checkboxes, grooups of checkboxes and groups of radio buttons as well.

This html/css, will allow you to also capture click on the label, so the checkbox will be checked and unchecked even if you click just on the label.

This type of checkbox/radio button works perfectly with any form, no problem at all. Have been tested using PHP, ASP.NET (.aspx), JavaServer Faces, and ColdFusion too.

This is simplest way and you can choose which checkboxes to give this style.

CSS:

.check-box input {
  display: none;
}

.check-box span:before {
  content: ' ';
  width: 20px;
  height: 20px;
  display: inline-block;
  background: url("unchecked.png");
}

.check-box input:checked + span:before {
  background: url("checked.png");
}

HTML:

<label class="check-box">
  <input type="checkbox">
  <span>Check box Text</span>
</label>

Since browsers like Edge and Firefox do not support :before :after on checkbox input tags, here is an alternative purely with HTML and CSS. Of course you should edit CSS according to your requirements.

Make the HTML for checkbox like this:

<div class='custom-checkbox'>
    <input type='checkbox' />
    <label>
        <span></span>
        Checkbox label
    </label>
</div>

Apply this style for the checkbox to change the color label

<style>
    .custom-checkbox {
        position: relative;
    }
    .custom-checkbox input{
        position: absolute;
        left: 0;
        top: 0;
        height:15px;
        width: 50px;    /* Expand the checkbox so that it covers */
        z-index : 1;    /* the label and span, increase z-index to bring it over */
        opacity: 0;     /* the label and set opacity to 0 to hide it. */
    }
    .custom-checkbox input+label {
        position: relative;
        left: 0;
        top: 0;
        padding-left: 25px;
        color: black;
    }
    .custom-checkbox input+label span {
        position: absolute;  /* a small box to display as checkbox */
        left: 0;
        top: 0;
        height: 15px;
        width: 15px;
        border-radius: 2px;
        border: 1px solid black;
        background-color: white;
    }
    .custom-checkbox input:checked+label { /* change label color when checked */
        color: orange;
    }
    .custom-checkbox input:checked+label span{ /* change span box color when checked */
        background-color: orange;
        border: 1px solid orange;
    }
</style>

Here is an example, with theme support. It is a modern approach with CSS transitions. There is absolutely no JavaScript required.

I derived the following code linked in this comment; on a related question.

Edit: I added radio buttons, as maxshuty suggests.

const selector = '.grid-container > .grid-row > .grid-col[data-theme="retro"]';
const main = () => {
  new CheckboxStyler().run(selector);
  new RadioStyler().run(selector);
};

/*
 * This is only used to add the wrapper class and checkmark span to an existing DOM,
 * to make this CSS work.
 */
class AbstractInputStyler {
  constructor(options) {
    this.opts = options;
  }
  run(parentSelector) {
    let wrapperClass = this.opts.wrapperClass;
    let parent = document.querySelector(parentSelector) || document.getElementsByTagName('body')[0];
    let labels = parent.querySelectorAll('label');
    if (labels.length) labels.forEach(label => {
      if (label.querySelector(`input[type="${this.opts._inputType}"]`)) {
        if (!label.classList.contains(wrapperClass)) {
          label.classList.add(wrapperClass);
          label.appendChild(this.__createDefaultNode());
        }
      }
    });
    return this;
  }
  /* @protected */
  __createDefaultNode() {
    let checkmark = document.createElement('span');
    checkmark.className = this.opts._activeClass;
    return checkmark;
  }
}

class CheckboxStyler extends AbstractInputStyler {
  constructor(options) {
    super(Object.assign({
      _inputType: 'checkbox',
      _activeClass: 'checkmark'
    }, CheckboxStyler.defaultOptions, options));
  }
}
CheckboxStyler.defaultOptions = {
  wrapperClass: 'checkbox-wrapper'
};

class RadioStyler extends AbstractInputStyler {
  constructor(options) {
    super(Object.assign({
      _inputType: 'radio',
      _activeClass: 'pip'
    }, RadioStyler.defaultOptions, options));
  }
}
RadioStyler.defaultOptions = {
  wrapperClass: 'radio-wrapper'
};

main();

/* Theming */

:root {
  --background-color: #FFF;
  --font-color: #000;
  --checkbox-default-background: #EEE;
  --checkbox-hover-background: #CCC;
  --checkbox-disabled-background: #AAA;
  --checkbox-selected-background: #1A74BA;
  --checkbox-selected-disabled-background: #6694B7;
  --checkbox-checkmark-color: #FFF;
  --checkbox-checkmark-disabled-color: #DDD;
}

[data-theme="dark"] {
  --background-color: #111;
  --font-color: #EEE;
  --checkbox-default-background: #222;
  --checkbox-hover-background: #444;
  --checkbox-disabled-background: #555;
  --checkbox-selected-background: #2196F3;
  --checkbox-selected-disabled-background: #125487;
  --checkbox-checkmark-color: #EEE;
  --checkbox-checkmark-disabled-color: #999;
}

[data-theme="retro"] {
  --background-color: #FFA;
  --font-color: #000;
  --checkbox-default-background: #EEE;
  --checkbox-hover-background: #FFF;
  --checkbox-disabled-background: #BBB;
  --checkbox-selected-background: #EEE;
  --checkbox-selected-disabled-background: #BBB;
  --checkbox-checkmark-color: #F44;
  --checkbox-checkmark-disabled-color: #D00;
}


/* General styles */

html {
  width: 100%;
  height: 100%;
}

body {
  /*background: var(--background-color); -- For demo, moved to column. */
  /*color:      var(--font-color);       -- For demo, moved to column. */
  background: #777;
  width: calc(100% - 0.5em);
  height: calc(100% - 0.5em);
  padding: 0.25em;
}

h1 {
  font-size: 1.33em !important;
}

h2 {
  font-size: 1.15em !important;
  margin-top: 1em;
}


/* Grid style - using flex */

.grid-container {
  display: flex;
  height: 100%;
  flex-direction: column;
  flex: 1;
}

.grid-row {
  display: flex;
  flex-direction: row;
  flex: 1;
  margin: 0.25em 0;
}

.grid-col {
  display: flex;
  flex-direction: column;
  height: 100%;
  padding: 0 1em;
  flex: 1;
  margin: 0 0.25em;
  /* If not demo, remove and uncomment the body color rules */
  background: var(--background-color);
  color: var(--font-color);
}

.grid-cell {
  width: 100%;
  height: 100%;
}


/* The checkbox wrapper */

.checkbox-wrapper,
.radio-wrapper {
  display: block;
  position: relative;
  padding-left: 1.5em;
  margin-bottom: 0.5em;
  cursor: pointer;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}


/* Hide the browser's default checkbox and radio buttons */

.checkbox-wrapper input[type="checkbox"] {
  position: absolute;
  opacity: 0;
  cursor: pointer;
  height: 0;
  width: 0;
}

.radio-wrapper input[type="radio"] {
  position: absolute;
  opacity: 0;
  cursor: pointer;
  height: 0;
  width: 0;
}


/* Create a custom checkbox */

.checkbox-wrapper .checkmark {
  position: absolute;
  top: 0;
  left: 0;
  height: 1em;
  width: 1em;
  background-color: var(--checkbox-default-background);
  transition: all 0.2s ease-in;
}

.radio-wrapper .pip {
  position: absolute;
  top: 0;
  left: 0;
  height: 1em;
  width: 1em;
  border-radius: 50%;
  background-color: var(--checkbox-default-background);
  transition: all 0.2s ease-in;
}


/* Disabled style */

.checkbox-wrapper input[type="checkbox"]:disabled~.checkmark,
.radio-wrapper input[type="radio"]:disabled~.pip {
  cursor: not-allowed;
  background-color: var(--checkbox-disabled-background);
  color: var(--checkbox-checkmark-disabled-color);
}

.checkbox-wrapper input[type="checkbox"]:disabled~.checkmark:after,
.radio-wrapper input[type="radio"]:disabled~.pip:after {
  color: var(--checkbox-checkmark-disabled-color);
}

.checkbox-wrapper input[type="checkbox"]:disabled:checked~.checkmark,
.radio-wrapper input[type="radio"]:disabled:checked~.pip {
  background-color: var(--checkbox-selected-disabled-background);
}


/* On mouse-over, add a grey background color */

.checkbox-wrapper:hover input[type="checkbox"]:not(:disabled):not(:checked)~.checkmark,
.radio-wrapper:hover input[type="radio"]:not(:disabled):not(:checked)~.pip {
  background-color: var(--checkbox-hover-background);
}


/* When the checkbox is checked, add a blue background */

.checkbox-wrapper input[type="checkbox"]:checked~.checkmark,
.radio-wrapper input[type="radio"]:checked~.pip {
  background-color: var(--checkbox-selected-background);
}


/* Create the checkmark/indicator (hidden when not checked) */

.checkbox-wrapper .checkmark:after {
  display: none;
  width: 100%;
  position: absolute;
  text-align: center;
  content: "\2713";
  color: var(--checkbox-checkmark-color);
  line-height: 1.1em;
}

.radio-wrapper .pip:after {
  display: none;
  width: 100%;
  position: absolute;
  text-align: center;
  content: "\2022";
  color: var(--checkbox-checkmark-color);
  font-size: 1.5em;
  top: -0.2em;
}


/* Show the checkmark when checked */

.checkbox-wrapper input[type="checkbox"]:checked~.checkmark:after {
  display: block;
  line-height: 1.1em;
}

.radio-wrapper input[type="radio"]:checked~.pip:after {
  display: block;
  line-height: 1.1em;
}

<link href="https://cdnjs.cloudflare.com/ajax/libs/normalize/8.0.1/normalize.min.css" rel="stylesheet" />
<div class="grid-container">
  <div class="grid-row">
    <div class="grid-col">
      <div class="grid-cell">
        <h1>Pure CSS</h1>
        <h2>Checkbox</h2>
        <label class="checkbox-wrapper">One
          <input type="checkbox" checked="checked">
          <span class="checkmark"></span>
        </label>
        <label class="checkbox-wrapper">Two
          <input type="checkbox">
          <span class="checkmark"></span>
        </label>
        <label class="checkbox-wrapper">Three
          <input type="checkbox" checked disabled>
          <span class="checkmark"></span>
        </label>
        <label class="checkbox-wrapper">Four
          <input type="checkbox" disabled>
          <span class="checkmark"></span>
        </label>
        <h2>Radio</h2>
        <label class="radio-wrapper">One
          <input type="radio" name="group-x">
          <span class="pip"></span>
        </label>
        <label class="radio-wrapper">Two
          <input type="radio" name="group-x">
          <span class="pip"></span>
        </label>
        <label class="radio-wrapper">Three
          <input type="radio" name="group-x" checked disabled>
          <span class="pip"></span>
        </label>
        <label class="radio-wrapper">Four
          <input type="radio" name="group-x" disabled>
          <span class="pip"></span>
        </label>
      </div>
    </div>
    <div class="grid-col" data-theme="dark">
      <div class="grid-cell">
        <h1>Pure CSS</h1>
        <h2>Checkbox</h2>
        <label class="checkbox-wrapper">One
          <input type="checkbox" checked="checked">
          <span class="checkmark"></span>
        </label>
        <label class="checkbox-wrapper">Two
          <input type="checkbox">
          <span class="checkmark"></span>
        </label>
        <label class="checkbox-wrapper">Three
          <input type="checkbox" checked disabled>
          <span class="checkmark"></span>
        </label>
        <label class="checkbox-wrapper">Four
          <input type="checkbox" disabled>
          <span class="checkmark"></span>
        </label>
        <h2>Radio</h2>
        <label class="radio-wrapper">One
          <input type="radio" name="group-y">
          <span class="pip"></span>
        </label>
        <label class="radio-wrapper">Two
          <input type="radio" name="group-y">
          <span class="pip"></span>
        </label>
        <label class="radio-wrapper">Three
          <input type="radio" name="group-y" checked disabled>
          <span class="pip"></span>
        </label>
        <label class="radio-wrapper">Four
          <input type="radio" name="group-y" disabled>
          <span class="pip"></span>
        </label>
      </div>
    </div>
    <div class="grid-col" data-theme="retro">
      <div class="grid-cell">
        <h1>JS + CSS</h1>
        <h2>Checkbox</h2>
        <label>One   <input type="checkbox" checked="checked"></label>
        <label>Two   <input type="checkbox"></label>
        <label>Three <input type="checkbox" checked disabled></label>
        <label>Four  <input type="checkbox" disabled></label>
        <h2>Radio</h2>
        <label>One   <input type="radio" name="group-z" checked="checked"></label>
        <label>Two   <input type="radio" name="group-z"></label>
        <label>Three <input type="radio" name="group-z" checked disabled></label>
        <label>Four  <input type="radio" name="group-z" disabled></label>
      </div>
    </div>
  </div>
</div>

Here's a modern version with a little animation, and simple styling you can customize:

.checkbox {
	position: relative;
	width: 20px;
	height: 20px;
	-webkit-appearance: none;
	-moz-appearance: none;
	-o-appearance: none;
	appearance: none;
	background: transparent;
	border: 2px solid #7C7A7D;
	border-radius: 5px;
	margin: 0;
	outline: none;
	transition: 0.5s ease;
    opacity: 0.8;
	cursor: pointer;
}


.checkbox:checked {
	border-color: #7C7A7D;
	background-color: #7C7A7D;
}


.checkbox:checked:before {
   position: absolute;
   left: 2px;
   top: -4px;
   display: block;
   content: '\2713';
   text-align: center;
   color: #FFF;
   font-family: Arial;
   font-size: 14px;
   font-weight: 800;
}


.checkbox:hover {
   opacity: 1.0;
   transform: scale(1.05);
}

Hide the input and add a before to the next element that create a checkbox equivalent

input[type="checkbox"] {
  display: none;    
}

input[type="checkbox"] + label:before {
  content:'';
  -webkit-appearance: none;
  background-color: transparent;
  border: 2px solid #0079bf;
  box-shadow: 0 1px 2px rgba(0, 0, 0, .05), inset 0px -15px 10px -12px rgba(0, 0, 0, 0.05);
  padding: 10px;
  display: inline-block;
  position: relative;
  vertical-align: middle;
  cursor: pointer;
  margin-right: 5px;
  background-color:red;
}

input[type="checkbox"]:checked + label:before {
  background-image: url("data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 8 8'%3E%3Cpath fill='%23fff' d='M6.564.75l-3.59 3.612-1.538-1.55L0 4.26 2.974 7.25 8 2.193z'/%3E%3C/svg%3E");
}

No, you still can't style the checkbox itself, but I (finally) figured out how to style an illusion while keeping the functionality of clicking a checkbox. It means that you can toggle it even if the cursor isn't perfectly still without risking selecting text or triggering drag-and-drop!

This solution probably also fits radio buttons.

The following works in Internet Explorer 9, Firefox 30.0 and Chrome 40.0.2214.91 and is just a basic example. You can still use it in combination with background images and pseudo-elements.

http://jsfiddle.net/o0xo13yL/1/

label {
    display: inline-block;
    position: relative; /* Needed for checkbox absolute positioning */
    background-color: #eee;
    padding: .5rem;
    border: 1px solid #000;
    border-radius: .375rem;
    font-family: "Courier New";
    font-size: 1rem;
    line-height: 1rem;
}

label > input[type="checkbox"] {
    display: block;
    position: absolute; /* Remove it from the flow */
    width: 100%;
    height: 100%;
    margin: -.5rem; /* Negative the padding of label to cover the "button" */
    cursor: pointer;
    opacity: 0; /* Make it transparent */
    z-index: 666; /* Place it on top of everything else */
}

label > input[type="checkbox"] + span {
    display: inline-block;
    width: 1rem;
    height: 1rem;
    border: 1px solid #000;
    margin-right: .5rem;
}

label > input[type="checkbox"]:checked + span {
    background-color: #666;
}

<label>
    <input type="checkbox" />
    <span>&nbsp;</span>Label text
</label>

<!DOCTYPE html>
<html>
<style>
/* The container */
.container {
  display: block;
  position: relative;
  padding-left: 35px;
  margin-bottom: 12px;
  cursor: pointer;
  font-size: 22px;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}

/* Hide the browser's default checkbox */
.container input {
  position: absolute;
  opacity: 0;
  cursor: pointer;
  height: 0;
  width: 0;
}

/* Create a custom checkbox */
.checkmark {
  position: absolute;
  top: 0;
  left: 0;
  height: 25px;
  width: 25px;
  background-color: white;
  border: 2px solid red;
}

/* On mouse-over, add a grey background color */
.container:hover input ~ .checkmark {
  background-color: #ccc;
}

/* When the checkbox is checked, add a white background */
.container input:checked ~ .checkmark {
  background-color: white;
}

/* Create the checkmark/indicator (hidden when not checked) */
.checkmark:after {
  content: "";
  position: absolute;
  display: none;
}

/* Show the checkmark when checked */
.container input:checked ~ .checkmark:after {
  display: block;
}

/* Style the checkmark/indicator */
.container .checkmark:after {
  left: 9px;
  top: 5px;
  width: 5px;
  height: 10px;
  border: solid green;
  border-width: 0 3px 3px 0;
  -webkit-transform: rotate(45deg);
  -ms-transform: rotate(45deg);
  transform: rotate(45deg);
}
</style>
<body>

<h1>Custom Checkboxes</h1>
<label class="container">One
  <input type="checkbox" checked="checked">
  <span class="checkmark"></span>
</label>
<label class="container">Two
  <input type="checkbox">
  <span class="checkmark"></span>
</label>
<label class="container">Three
  <input type="checkbox">
  <span class="checkmark"></span>
</label>
<label class="container">Four
  <input type="checkbox">
  <span class="checkmark"></span>
</label>

</body>
</html>

This helped me to change style (color) for checkbox

input[type=checkbox] {
  accent-color: red;
}

We can also use the same for radio buttons.

input[type=checkbox].css-checkbox {
    position: absolute;
    overflow: hidden;
    clip: rect(0 0 0 0);
    height: 1px;
    width: 1px;
    margin: -1px;
    padding: 0;
    border: 0;
}

input[type=checkbox].css-checkbox + label.css-label {
    padding-left: 20px;
    height: 15px;
    display: inline-block;
    line-height: 15px;
    background-repeat: no-repeat;
    background-position: 0 0;
    font-size: 15px;
    vertical-align: middle;
    cursor: pointer;
}

input[type=checkbox].css-checkbox:checked + label.css-label {
    background-position: 0 -15px;
}

.css-label{
    background-image:url(http://csscheckbox.com/checkboxes/dark-check-green.png);
}

It seems you can change the colour of the checkbox in grayscale by using CSS only.

The following converts the checkboxes from black to gray (which was about what I wanted):

input[type="checkbox"] {
    opacity: .5;
}

You can use iCheck. It is customized checkboxes and radio buttons for jQuery & Zepto, and maybe it will help you.

Make sure jQuery v1.7+ is loaded before the icheck.js

1. Choose a color scheme, there are 10 different styles available:

   • Black — minimal.css
   • Red — red.css
   • Green — green.css
   • Blue — blue.css
   • Aero — aero.css
   • Grey — grey.css
   • Orange — orange.css
   • Yellow — yellow.css
   • Pink — pink.css
   • Purple — purple.css

2. Copy /skins/minimal/ folder and icheck.js file to your site.

3. Insert before in your HTML (replace your-path and color-scheme):

   <link href="your-path/minimal/color-scheme.css" rel="stylesheet">
   <script src="your-path/icheck.js"></script>
   

   Example for a Red color scheme:

   <link href="your-path/minimal/red.css" rel="stylesheet">
   <script src="your-path/icheck.js"></script>
   

4. Add some checkboxes and radio buttons to your HTML:

   <input type="checkbox">
   <input type="checkbox" checked>
   <input type="radio" name="iCheck">
   <input type="radio" name="iCheck" checked>
   

5. Add JavaScript to your HTML to launch iCheck plugin:

   <script>
       $(document).ready(function(){
         $('input').iCheck({
           checkboxClass: 'icheckbox_minimal',
           radioClass: 'iradio_minimal',
           increaseArea: '20%' // Optional
         });
      });
   </script>
   

6. For different from black color schemes use this code (example for Red):

   <script>
       $(document).ready(function(){
         $('input').iCheck({
           checkboxClass: 'icheckbox_minimal-red',
           radioClass: 'iradio_minimal-red',
           increaseArea: '20%' // Optional
         });
      });
   </script>
   

7. Done

Warning: the following was true at the time of writing, but in the meantime things have progressed.

AFAIK modern browsers display checkboxes using the native OS control, so there's no way to style them.

This will make the dotted border, aswell as the background your seeking, also, if you want to set a specific background color for when checked, simply set it where apropriate in below example for your issue :) This solution also sets in a custom checkmark icon, etc.

for an html element like: <input type="checkbox" />

input[type='checkbox']:checked {
  background-color: rgb(60,69,77,0.9);
}
input[type='checkbox']:checked:after {
  content: '\2713';
  color:white;
}
input[type='checkbox']{
  background:#ff0000;
  text-align: center;
  display: table-cell;
  vertical-align: middle;
  width: 20px !important;
  height: 20px !important;
  appearance:none;
  border-radius:10%;
  border: 1px dotted rgb(60,69,77,0.9);
  box-shadow: none;
  font-size: 1em;
}

Quick fix to add icon in front of text:

< asp:CheckBox... Text="< img src='/link/to/img.png' />My Text" />