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.
npm install happy-domA JavaScript implementation of a web browser without its graphical user interface.
- Custom Elements (Web Components)
- Declarative Shadow DOM
- Mutation Observer
- Tree Walker
- Fetch API
And much more..
Documentation | Getting Started | Setup as Test Environment | GitHub
Vitest | Bun | Jest | Testing Library | Google LitElement | Vue | React | Svelte | Angular
| 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(':nth-child(2n+1)') | 10.4 ms | 3.8 ms |
See how the test was done here