> For the complete documentation index, see [llms.txt](https://webcomp.gitbook.io/webcomp/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://webcomp.gitbook.io/webcomp/shadow-dom.md).

# Shadow DOM

By default WebComp components don't use Shadow DOM because polyfill for it in some browsers may be a bit expensive.

If you know what you doing and want to use Shadow DOM, all you need to do is pass an options object with `useShadow` when registering:

```javascript
WebComp.register(MyComponent, 'my-component', {
  useShadow: 'open',
});
```

## Modes

* `useShadow: 'open'` will enable Shadow DOM that is accessible from outside JavaScript.
* `useShadow: 'closed'` will enable Shadow DOM that is unaccessible and unchangeable from JavaScript.