cure53/dompurifyDOMPurify - a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMPurify works with a secure default, but offers a lot of configurability and hooks. Demo:
DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG.
It's also very simple to use and get started with. DOMPurify was started in February 2014 and, meanwhile, has reached version v3.4.15.
DOMPurify runs as JavaScript and works in all modern browsers (Safari (10+), Opera (15+), Edge, Firefox and Chrome - as well as almost anything else using Blink, Gecko or WebKit). It doesn't break on MSIE or other legacy browsers. It simply does nothing.
Note that DOMPurify v2.5.9 is the latest version supporting MSIE. For important security updates compatible with MSIE, please use the 2.x branch.
Our automated tests cover 9 browser/OS combinations on the current engines (Chromium, Firefox, and WebKit across Ubuntu, macOS, and Windows) on every push, and a separate matrix re-runs the suite on older engine snapshots (back to roughly Chromium 110, Firefox 108 and WebKit 16.4, around three years old) so regressions on outdated browsers get caught too. We also run Node.js v20, v22, v24, v25 and v26 with DOMPurify on jsdom. Older Node versions are known to work as well, but hey... no guarantees.
DOMPurify is written by security people who have vast background in web attacks and XSS. Fear not. For more details please also read about our Security Goals & Threat Model. Please, read it. Like, really. And if you enjoy the gory details, the Attack Classes & Bypass History page catalogs the parser-mutation, namespace, clobbering, and template tricks DOMPurify defends against.
The DOMPurify project inspired the creation of the HTML Sanitizer API, which is already shipping in many browsers. The same capability is now being standardized directly in the WHATWG HTML specification.
DOMPurify sanitizes HTML and prevents XSS attacks. You can feed DOMPurify with e.g. a string full of dirty HTML and it will return a string (unless configured otherwise) with clean HTML. DOMPurify will strip out everything that contains dangerous HTML and thereby prevent XSS attacks and other nastiness. It's also damn bloody fast. We use the technologies the browser provides and turn them into an XSS filter. The faster your browser, the faster DOMPurify will be.
It's easy. Just include DOMPurify on your website.
<script type="text/javascript" src="dist/purify.js"></script>
<script type="text/javascript" src="dist/purify.min.js"></script>
Afterwards you can sanitize strings by executing the following code:
const clean = DOMPurify.sanitize(dirty);
Or maybe this, if you love working with Angular or alike:
import DOMPurify from 'dompurify';
const clean = DOMPurify.sanitize('<b>hello there</b>');
The resulting HTML can be written into a DOM element using innerHTML or the DOM using document.write(). That is fully up to you.
Note that by default, we permit HTML, SVG and MathML. If you only need HTML, which might be a very common use-case, you can easily set that up as well:
const clean = DOMPurify.sanitize(dirty, { USE_PROFILES: { html: true } });
Well, please note, if you first sanitize HTML and then modify it afterwards, you might easily void the effects of sanitization. If you feed the sanitized markup to another library after sanitization, please be certain that the library doesn't mess around with the HTML on its own. See the Security Goals & Threat Model for safe-usage recipes and the tags/attributes worth thinking twice about, and Attack Classes & Bypass History for why post-processing and changing the markup context defeat sanitization.
After sanitizing your markup, you can also have a look at the property DOMPurify.removed and find out, what elements and attributes were thrown out. Please do not use this property for making any security critical decisions. This is just a little helper for curious minds.
DOMPurify technically also works server-side with Node.js. Our support strives to follow the Node.js release cycle.
Running DOMPurify on the server requires a DOM to be present, which is probably no surprise. Usually, jsdom is the tool of choice and we strongly recommend to use the latest version of jsdom.
Why? Because older versions of jsdom are known to be buggy in ways that result in XSS even if DOMPurify does everything 100% correctly. There are known attack vectors in, e.g. jsdom v19.0.0 that are fixed in jsdom v20.0.0 - and we really recommend to keep jsdom up to date because of that.