How to decode HTML entities using jQuery?
JavascriptJqueryHtmlJavascript Problem Overview
How do I use jQuery to decode HTML entities in a string?
Javascript Solutions
Solution 1 - Javascript
> Security note: using this answer (preserved in its original form below) may introduce an XSS vulnerability into your application. You should not use this answer. Read lucascaro's answer for an explanation of the vulnerabilities in this answer, and use the approach from either that answer or Mark Amery's answer instead.
Actually, try
var encodedStr = "This is fun & stuff";
var decoded = $("<div/>").html(encodedStr).text();
console.log(decoded);
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div/>
Solution 2 - Javascript
Without any jQuery:
function decodeEntities(encodedString) {
var textArea = document.createElement('textarea');
textArea.innerHTML = encodedString;
return textArea.value;
}
console.log(decodeEntities('1 & 2')); // '1 & 2'
This works similarly to the accepted answer, but is safe to use with untrusted user input.
Security issues in similar approaches
As noted by Mike Samuel, doing this with a <div>
instead of a <textarea>
with untrusted user input is an XSS vulnerability, even if the <div>
is never added to the DOM:
function decodeEntities(encodedString) {
var div = document.createElement('div');
div.innerHTML = encodedString;
return div.textContent;
}
// Shows an alert
decodeEntities('<img src="nonexistent_image" onerror="alert(1337)">')
However, this attack is not possible against a <textarea>
because there are no HTML elements that are permitted content of a <textarea>
. Consequently, any HTML tags still present in the 'encoded' string will be automatically entity-encoded by the browser.
function decodeEntities(encodedString) {
var textArea = document.createElement('textarea');
textArea.innerHTML = encodedString;
return textArea.value;
}
// Safe, and returns the correct answer
console.log(decodeEntities('<img src="nonexistent_image" onerror="alert(1337)">'))
> Warning: Doing this using jQuery's .html()
and .val()
methods instead of using .innerHTML
and .value
is also insecure* for some versions of jQuery, even when using a textarea
. This is because older versions of jQuery would deliberately and explicitly evaluate scripts contained in the string passed to .html()
. Hence code like this shows an alert in jQuery 1.8:
//<!-- CDATA
// Shows alert
$("<textarea>")
.html("<script>alert(1337);</script>")
.text();
//-->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.2.3/jquery.min.js"></script>
* Thanks to Eru Penkman for catching this vulnerability.
Solution 3 - Javascript
Like Mike Samuel said, don't use jQuery.html().text() to decode html entities as it's unsafe.
Instead, use a template renderer like Mustache.js or decodeEntities from @VyvIT's comment.
Underscore.js utility-belt library comes with escape
and unescape
methods, but they are not safe for user input:
Solution 4 - Javascript
I think you're confusing the text and HTML methods. Look at this example, if you use an element's inner HTML as text, you'll get decoded HTML tags (second button). But if you use them as HTML, you'll get the HTML formatted view (first button).
<div id="myDiv">
here is a <b>HTML</b> content.
</div>
<br />
<input value="Write as HTML" type="button" onclick="javascript:$('#resultDiv').html($('#myDiv').html());" />
<input value="Write as Text" type="button" onclick="javascript:$('#resultDiv').text($('#myDiv').html());" />
<br /><br />
<div id="resultDiv">
Results here !
</div>
First button writes : here is a HTML content.
Second button writes : here is a <B>HTML</B> content.
By the way, you can see a plug-in that I found in jQuery plugin - HTML decode and encode that encodes and decodes HTML strings.
Solution 5 - Javascript
The question is limited by 'with jQuery' but it might help some to know that the jQuery code given in the best answer here does the following underneath...this works with or without jQuery:
function decodeEntities(input) {
var y = document.createElement('textarea');
y.innerHTML = input;
return y.value;
}
Solution 6 - Javascript
You can use the he library, available from https://github.com/mathiasbynens/he
Example:
console.log(he.decode("Jörg & Jürgen rocked to & fro "));
// Logs "Jörg & Jürgen rocked to & fro"
I challenged the library's author on the question of whether there was any reason to use this library in clientside code in favour of the <textarea>
hack provided in other answers here and elsewhere. He provided a few possible justifications:
-
If you're using node.js serverside, using a library for HTML encoding/decoding gives you a single solution that works both clientside and serverside.
-
Some browsers' entity decoding algorithms have bugs or are missing support for some named character references. For example, Internet Explorer will both decode and render non-breaking spaces (
) correctly but report them as ordinary spaces instead of non-breaking ones via a DOM element'sinnerText
property, breaking the<textarea>
hack (albeit only in a minor way). Additionally, IE 8 and 9 simply don't support any of the new named character references added in HTML 5. The author of he also hosts a test of named character reference support at http://mathias.html5.org/tests/html/named-character-references/. In IE 8, it reports over one thousand errors.If you want to be insulated from browser bugs related to entity decoding and/or be able to handle the full range of named character references, you can't get away with the
<textarea>
hack; you'll need a library like he. -
He just darn well feels like doing things this way is less hacky.
Solution 7 - Javascript
encode:
$("<textarea/>").html('<a>').html(); // return '<a>'
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<textarea/>
decode:
$("<textarea/>").html('<a>').val() // return '<a>'
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<textarea/>
Solution 8 - Javascript
Use
myString = myString.replace( /\&/g, '&' );
It is easiest to do it on the server side because apparently JavaScript has no native library for handling entities, nor did I find any near the top of search results for the various frameworks that extend JavaScript.
Search for "JavaScript HTML entities", and you might find a few libraries for just that purpose, but they'll probably all be built around the above logic - replace, entity by entity.
Solution 9 - Javascript
Try this :
var htmlEntities = "<script>alert('hello');</script>";
var htmlDecode =$.parseHTML(htmlEntities)[0]['wholeText'];
console.log(htmlDecode);
Solution 10 - Javascript
I just had to have an HTML entity charater (⇓) as a value for a HTML button. The HTML code looks good from the beginning in the browser:
<input type="button" value="Embed & Share ⇓" id="share_button" />
Now I was adding a toggle that should also display the charater. This is my solution
$("#share_button").toggle(
function(){
$("#share").slideDown();
$(this).attr("value", "Embed & Share " + $("<div>").html("⇑").text());
}
This displays ⇓ again in the button. I hope this might help someone.
Solution 11 - Javascript
You have to make custom function for html entities:
function htmlEntities(str) {
return String(str).replace(/&/g, '&').replace(/</g, '<').replace(/>/g,'>').replace(/"/g, '"');
}
Solution 12 - Javascript
Suppose you have below String.
Our Deluxe cabins are warm, cozy & comfortable
var str = $("p").text(); // get the text from <p> tag
$('p').html(str).text(); // Now,decode html entities in your variable i.e
str and assign back to
tag.
that's it.
Solution 13 - Javascript
For ExtJS users, if you already have the encoded string, for example when the returned value of a library function is the innerHTML content, consider this ExtJS function:
Ext.util.Format.htmlDecode(innerHtmlContent)
Solution 14 - Javascript
Extend a String class:
String::decode = ->
$('<textarea />').html(this).text()
and use as method:
"<img src='myimage.jpg'>".decode()
Solution 15 - Javascript
You don't need jQuery to solve this problem, as it creates a bit of overhead and dependency.
I know there are a lot of good answers here, but since I have implemented a bit different approach, I thought to share.
This code is a perfectly safe security-wise approach, as the escaping handler depends on the browser, instead on the function. So, if some vulnerability will be discovered in the future, this solution is covered.
const decodeHTMLEntities = text => {
// Create a new element or use one from cache, to save some element creation overhead
const el = decodeHTMLEntities.__cache_data_element
= decodeHTMLEntities.__cache_data_element
|| document.createElement('div');
const enc = text
// Prevent any mixup of existing pattern in text
.replace(/⪪/g, '⪪#')
// Encode entities in special format. This will prevent native element encoder to replace any amp characters
.replace(/&([a-z1-8]{2,31}|#x[0-9a-f]+|#\d+);/gi, '⪪$1⪫');
// Encode any HTML tags in the text to prevent script injection
el.textContent = enc;
// Decode entities from special format, back to their original HTML entities format
el.innerHTML = el.innerHTML
.replace(/⪪([a-z1-8]{2,31}|#x[0-9a-f]+|#\d+)⪫/gi, '&$1;')
.replace(/⪪#/g, '⪪');
// Get the decoded HTML entities
const dec = el.textContent;
// Clear the element content, in order to preserve a bit of memory (in case the text is big)
el.textContent = '';
return dec;
}
// Example
console.log(decodeHTMLEntities("<script>alert('∳∳∳∳⪪#x02233⪫');</script>"));
// Prints: <script>alert('∳∳∳∳⪪#x02233⪫');</script>
By the way, I have chosen to use the characters ⪪
and ⪫
, because they are rarely used, so the chance of impacting the performance by matching them is significantly lower.
Solution 16 - Javascript
Here are still one problem: Escaped string does not look readable when assigned to input value
var string = _.escape("<img src=fake onerror=alert('boo!')>");
$('input').val(string);
Exapmle: https://jsfiddle.net/kjpdwmqa/3/
Solution 17 - Javascript
Alternatively, theres also a library for it..
here, https://cdnjs.com/libraries/he
npm install he //using node.js
<script src="js/he.js"></script> //or from your javascript directory
The usage is as follows...
//to encode text
he.encode('© Ande & Nonso® Company LImited 2018');
//to decode the
he.decode('© Ande & Nonso® Company Limited 2018');
cheers.
Solution 18 - Javascript
To decode HTML Entities with jQuery, just use this function:
function html_entity_decode(txt){
var randomID = Math.floor((Math.random()*100000)+1);
$('body').append('<div id="random'+randomID+'"></div>');
$('#random'+randomID).html(txt);
var entity_decoded = $('#random'+randomID).html();
$('#random'+randomID).remove();
return entity_decoded;
}
How to use:
Javascript:
var txtEncoded = "á é í ó ú";
$('#some-id').val(html_entity_decode(txtEncoded));
HTML:
<input id="some-id" type="text" />
Solution 19 - Javascript
The easiest way is to set a class selector to your elements an then use following code:
$(function(){
$('.classSelector').each(function(a, b){
$(b).html($(b).text());
});
});
Nothing any more needed!
I had this problem and found this clear solution and it works fine.
Solution 20 - Javascript
I think that is the exact opposite of the solution chosen.
var decoded = $("<div/>").text(encodedStr).html();