Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. It includes many web standards from WHATWG DOM and HTML.
The goal of Happy DOM is to emulate enough of a web browser to be useful for testing, scraping web sites and server-side rendering.
Happy DOM focuses heavily on performance and can be used as an alternative to JSDOM.
Read more about how to use Happy DOM
Custom Elements (Web Components)
Shadow Root (Shadow DOM)
Declarative Shadow DOM
Mutation Observer
Tree Walker
Fetch
And much more..
This repository is a Monorepo. Each package lives under packages/<package>
.
This package contains the core functionality of Happy DOM.
This package makes it possible to use Happy DOM with Jest.
A utility that registers Happy DOM globally, which makes it possible to use Happy DOM for testing in a Node environment.
This package has been deprecated.
Happy DOM now supports Declarative Shadow DOM which can be used for server-side rendering of web components.
Operation | JSDOM | Happy DOM |
---|---|---|
Import / Require | 333 ms | 45 ms |
Parse HTML | 256 ms | 26 ms |
Serialize HTML | 65 ms | 8 ms |
Render custom element | 214 ms | 19 ms |
querySelectorAll('tagname') | 4.9 ms | 0.7 ms |
querySelectorAll('.class') | 6.4 ms | 3.7 ms |
querySelectorAll('[attribute]') | 4.0 ms | 1.7 ms |
querySelectorAll('[class~="name"]') | 5.5 ms | 2.9 ms |
querySelectorAll(':nth-child(2n+1)') | 10.4 ms | 3.8 ms |
See how the test was done here