Deno DOM

An implementation of the browser DOM—primarily for SSR—in Deno. Implemented with Rust, WASM, and obviously, Deno/TypeScript.


import { DOMParser, Element } from "";

const doc = new DOMParser().parseFromString(`
  <h1>Hello World!</h1>
  <p>Hello from <a href="">Deno!</a></p>
`, "text/html")!;

const p = doc.querySelector("p")!;

console.log(p.textContent); // "Hello from Deno!"
console.log(p.childNodes[1].textContent); // "Deno!"

p.innerHTML = "DOM in <b>Deno</b> is pretty cool";
console.log(p.children[0].outerHTML); // "<b>Deno</b>"

Deno DOM has two backends, WASM and native using Deno native plugins. Both APIs are identical, the difference being only in performance. The WASM backend works with all Deno restrictions, but the native backend requires the --unstable --allow-plugin flags. You can switch between them by importing either deno-dom-wasm.ts or deno-dom-native.ts.

Deno DOM is still under development, but is fairly usable for basic HTML manipulation needs.


  • HTML parser in Deno
  • Fast
  • Mirror most* supported DOM APIs as closely as possible
  • Provide specific APIs in addition to DOM APIs to make certain operations more efficient, like controlling Shadow DOM (see Open Questions)
  • Use cutting-edge JS features like private class members, optional chaining, etc


  • Headless browser implementation
  • Ability to run JS embedded in documents (<script> tags, onload, etc)
  • Parse CSS or JS (they're just text, but this may be supported in the future for CSSOM)
  • Support older (or even not so old) JS engines. In other words, there will be no support of transpilation to ES5, no support of polyfills, etc
  • Support special functionality of obsolet HTML elements (<marquee>, etc)


  • html5ever developers for the HTML parser
  • nwsapi developers for the selector parser