How can I make a CSS glass/blur effect work for an overlay?
HtmlCssBlurCss FiltersHtml Problem Overview
I am having trouble applying a blur effect on a semi-transparent overlay div. I'd like everything behind the div the be blurred, like this:
Here is a jsfiddle which doesn't work: http://jsfiddle.net/u2y2091z/
Any ideas how to make this work? I'd like to keep this as uncomplicated as possible and have it be cross-browser. Here is the CSS I'm using:
#overlay {
position: absolute;
left: 0;
top: 0;
right: 0;
bottom: 0;
background:black;
background:rgba(0,0,0,0.8);
filter:blur(4px);
-o-filter:blur(4px);
-ms-filter:blur(4px);
-moz-filter:blur(4px);
-webkit-filter:blur(4px);
}
Html Solutions
Solution 1 - Html
For a more simple and up to date answer:
backdrop-filter: blur(6px);
Note browser support is not perfect but in most cases a blur would be non essential.
Solution 2 - Html
Here is an example that uses svg filter.
The idea is to use an svg element with height same as the #overlay and apply the feGaussianblur filter on it. This filter is applied on an svg image element. To give it an extruded effect, you could use a box-shadow at the bottom of the overlay.
Browser Support for svg filters.
Demo on Codepen
body {
background: #222222;
}
#container {
position: relative;
width: 450px;
margin: 0 auto;
}
img {
height: 300px;
}
#overlay {
position: absolute;
left: 0;
top: 0;
width: 100%;
z-index: 1;
color: rgba(130, 130, 130, 0.5);
font-size: 50px;
text-align: center;
line-height: 100px;
box-shadow: 0 3px 5px rgba(0, 0, 0, 0.3);
}
<div id="container">
<img src="http://lorempixel.com/450/300/sports" />
<div id="overlay">WET</div>
<svg width="450" height="100" viewBox="0 0 450 100" style="position: absolute; top: 0;">
<defs>
<filter id="blur">
<feGaussianBlur in="SourceGraphic" stdDeviation="3" />
</filter>
</defs>
<image filter="url(#blur)" xlink:href="http://lorempixel.com/450/300/sports" x="0" y="0" height="300px" width="450px" />
</svg>
</div>
Solution 3 - Html
I was able to piece together information from everyone here and further Googling, and I came up with the following which works in Chrome and Firefox: http://jsfiddle.net/xtbmpcsu/. I'm still working on making this work for IE and Opera.
The key is putting the content inside of the div to which the filter is applied:
body {
background: #300000;
background: linear-gradient(45deg, #300000, #000000, #300000, #000000);
color: white;
}
#mask {
position: absolute;
left: 0;
top: 0;
right: 0;
bottom: 0;
background-color: black;
opacity: 0.5;
}
img {
filter: blur(10px);
-webkit-filter: blur(10px);
-moz-filter: blur(10px);
-o-filter: blur(10px);
-ms-filter: blur(10px);
position: absolute;
left: 100px;
top: 100px;
height: 300px;
width: auto;
}
<div id="mask">
<p>Lorem ipsum ...</p>
<img src="http://www.byui.edu/images/agriculture-life-sciences/flower.jpg" />
</div>
So mask has the filters applied. Also, note the use of url() for a filter with an <svg> tag for the value -- that idea came from http://codepen.io/AmeliaBR/pen/xGuBr. If you happen to minify your CSS, you might need to replace any spaces in the SVG filter markup with "%20".
So now, everything inside the mask div is blurred.
Solution 4 - Html
background: rgba(255,255,255,0.5);
backdrop-filter: blur(5px);
Instead of adding another blur background to your content, you can use backdrop-filter. FYI IE 11 and Firefox may not support it. Check caniuse.
Demo:
header {
position: fixed;
width: 100%;
padding: 10px;
background: rgba(255,255,255,0.5);
backdrop-filter: blur(5px);
}
body {
margin: 0;
}
<header>
Header
</header>
<div>
<img src="https://dummyimage.com/600x400/000/fff" />
<img src="https://dummyimage.com/600x400/000/fff" />
<img src="https://dummyimage.com/600x400/000/fff" />
</div>
Solution 5 - Html
If you're looking for a reliable cross-browser approach today, you won't find a great one. The best option you have is to create two images (this could be automated in some environments), and arrange them such that one overlays the other. I've created a simple example below:
<figure class="js">
<img src="http://i.imgur.com/3oenmve.png" />
<img src="http://i.imgur.com/3oenmve.png?1" class="blur" />
</figure>
figure.js {
position: relative;
width: 250px; height: 250px;
}
figure.js .blur {
top: 0; left: 0;
position: absolute;
clip: rect( 0, 250px, 125px, 0 );
}
Though effective, even this approach isn't necessarily ideal. That being said, it does yield the desired result.
Solution 6 - Html
Here's a possible solution.
HTML
<img id="source" src="http://www.byui.edu/images/agriculture-life-sciences/flower.jpg" />
<div id="crop">
<img id="overlay" src="http://www.byui.edu/images/agriculture-life-sciences/flower.jpg" />
</div>
CSS
#crop {
overflow: hidden;
position: absolute;
left: 100px;
top: 100px;
width: 450px;
height: 150px;
}
#overlay {
-webkit-filter:blur(4px);
filter:blur(4px);
width: 450px;
}
#source {
height: 300px;
width: auto;
position: absolute;
left: 100px;
top: 100px;
}
I know the CSS can be simplified and you probably should get rid of the ids. The idea here is to use a div as a cropping container and then apply blur on duplicate of the image. Fiddle
To make this work in Firefox, you would have to use SVG hack.
Solution 7 - Html
This will do the blur overlay over the content:
.blur {
display: block;
bottom: 0;
left: 0;
position: fixed;
right: 0;
top: 0;
-webkit-backdrop-filter: blur(15px);
backdrop-filter: blur(15px);
background-color: rgba(0, 0, 0, 0.5);
}
Solution 8 - Html
From backdrop-filter
> ...apply graphical effects such as blurring or color shifting to the area > behind an element. Because it applies to everything behind the > element, to see the effect you must make the element or its background > at least partially transparent.
Solution 9 - Html
#bg, #search-bg {
background-image: url('https://images.pexels.com/photos/719609/pexels-photo-719609.jpeg?w=940&h=650&auto=compress&cs=tinysrgb');
background-repeat: no-repeat;
background-size: 1080px auto;
}
#bg {
background-position: center top;
padding: 70px 90px 120px 90px;
}
#search-container {
position: relative;
}
#search-bg {
/* Absolutely position it, but stretch it to all four corners, then put it just behind #search's z-index */
position: absolute;
top: 0px;
right: 0px;
bottom: 0px;
left: 0px;
z-index: 99;
/* Pull the background 70px higher to the same place as #bg's */
background-position: center -70px;
-webkit-filter: blur(10px);
filter: url('/media/blur.svg#blur');
filter: blur(10px);
}
#search {
/* Put this on top of the blurred layer */
position: relative;
z-index: 100;
padding: 20px;
background: rgb(34,34,34); /* for IE */
background: rgba(34,34,34,0.75);
}
@media (max-width: 600px ) {
#bg { padding: 10px; }
#search-bg { background-position: center -10px; }
}
#search h2, #search h5, #search h5 a { text-align: center; color: #fefefe; font-weight: normal; }
#search h2 { margin-bottom: 50px }
#search h5 { margin-top: 70px }
<div id="bg">
<div id="search-container">
<div id="search-bg"></div>
<div id="search">
<h2>Awesome</h2>
<h5><a href="#">How it works »</a></h5>
</div>
</div>
</div>
Solution 10 - Html
I came up with this solution.
Click to view image of blurry effect
It is kind of a trick which uses an absolutely positioned child div, sets its background image same as the parent div and then uses the background-attachment:fixed CSS property together with the same background properties set on the parent element.
Then you apply filter:blur(10px) (or any value) on the child div.
*{
margin:0;
padding:0;
box-sizing: border-box;
}
.background{
position: relative;
width:100%;
height:100vh;
background-image:url('https://images.unsplash.com/photo-1547937414-009abc449011?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=1350&q=80');
background-size:cover;
background-position: center;
background-repeat:no-repeat;
}
.blur{
position: absolute;
top:0;
left:0;
width:50%;
height:100%;
background-image:url('https://images.unsplash.com/photo-1547937414-009abc449011?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=1350&q=80');
background-position: center;
background-repeat: no-repeat;
background-attachment: fixed;
background-size:cover;
filter:blur(10px);
transition:filter .5s ease;
backface-visibility: hidden;
}
.background:hover .blur{
filter:blur(0);
}
.text{
display: inline-block;
font-family: sans-serif;
color:white;
font-weight: 600;
text-align: center;
position: relative;
left:25%;
top:50%;
transform:translate(-50%,-50%);
}
<head>
<title>Blurry Effect</title>
</head>
<body>
<div class="background">
<div class="blur"></div>
<h1 class="text">This is the <br>blurry side</h1>
</div>
</body>
Solution 11 - Html
Here's a solution that works with fixed backgrounds, if you have a fixed background and you have some overlayed elements and you need blured backgrounds for them, this solution works:
Image we have this simple HTML:
<body> <!-- or any wrapper -->
<div class="content">Some Texts</div>
</body>
A fixed background for <body> or the wrapper element:
body {
background-image: url(http://placeimg.com/640/360/any);
background-size: cover;
background-repeat: no-repeat;
background-attachment: fixed;
}
And here for example we have a overlayed element with a white transparent background:
.content {
background-color: rgba(255, 255, 255, 0.3);
position: relative;
}
Now we need to use the exact same background image of our wrapper for our overlay elements too, i use it as a :before psuedo-class:
.content:before {
content: '';
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
z-index: -1;
filter: blur(5px);
background-image: url(http://placeimg.com/640/360/any);
background-size: cover;
background-repeat: no-repeat;
background-attachment: fixed;
}
Since the fixed background works in a same way in both wrapper and overlayed elements, we have the background in exactly same scroll position of the overlayed element and we can simply blur it. Here's a working fiddle, tested in Firefox, Chrome, Opera and Edge: https://jsfiddle.net/0vL2rc4d/
NOTE: In firefox there's a bug that makes screen flicker when scrolling and there are fixed blurred backgrounds. if there's any fix, let me know