GitHub - kkomelin/isomorphic-dompurify: Use DOMPurify on server and client in the same way

Isomorphic DOMPurify

The library makes it possible to seamlessly use DOMPurify on server and client in the same way. It does nothing by itself except providing an isomorphic/universal wrapper around DOMPurify, so all credits go to DOMPurify authors and contributors.

DOMPurify - 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.

Motivation

DOMPurify needs a DOM tree to base on, which is not available in Node by default. To work on the server side, we need a fake DOM to be created and supplied to DOMPurify. It means that DOMPurify initialization logic on the server is not the same as on the client.

This project was born with the idea of encapsulating DOMPurify initialization details and providing an easy way to import the library on both, server and client, for example in Next.js apps.

It was inspired by Isomorphic Unfetch.

Requirements

isomorphic-dompurify	Node.js	Environment
`<=0.19.0`	`>=12`	Server
`>=0.20.0`	`>=14`	Server
`>=1.4.0`	`>=16`	Server
`>=1.10.0`	`>=18`	Server
`>=2.27.0`	`>=20`	Server
`>=2.30.0`	`>=20.19.5`	Server
`>=3.0.0`	`^20.19.0 \|\| ^22.12.0 \|\| >=24.0.0`	Server

Installation

$ npm i isomorphic-dompurify

Updates

Please note that DOMPurify library doesn't follow Semantic Versioning, so we have to release every change as a minor version because we cannot be 100% sure whether new features are added to patch DOMPurify releases or not.

Usage

import DOMPurify from "isomorphic-dompurify";

const clean = DOMPurify.sanitize(dirtyString);

You can pass config as a second argument:

const clean = DOMPurify.sanitize(dirtyString, { USE_PROFILES: { html: true } });

Named imports are also supported:

import { sanitize } from "isomorphic-dompurify";

const clean = sanitize(dirtyString);

Memory Management (Server)

In long-running Node.js processes, the internal jsdom window accumulates DOM state across sanitization calls, which can cause progressive slowdown and memory growth. Use clearWindow() to periodically release these resources:

import { sanitize, clearWindow } from "isomorphic-dompurify";

// Sanitize as usual
const clean = sanitize(dirtyString);

// Release jsdom resources when appropriate (e.g. after a request, after a batch)
clearWindow();

clearWindow() closes the current jsdom window and creates a fresh one. All import styles (default and named) continue to work after calling it.

Note: Any hooks or config set via addHook/setConfig will need to be re-applied after calling clearWindow(). In the browser build, clearWindow() is a no-op.

Web Worker Support

The isomorphic-dompurify library is compatible with Web Workers, however, dompurify, which it depends upon, is not, at least not yet.

Playgrounds

Want to try isomorphic-dompurify with your favorite framework? Check out isomorphic-dompurify-playgrounds — minimal setups for popular frameworks including Astro, Next.js, Nuxt, React and Svelte.