# Side Panel
[Chrome Docs](https://developer.chrome.com/docs/extensions/reference/sidePanel/) • [Firefox Docs](https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/user_interface/Sidebars)
In Chrome, side panels use the "side_panel" API, while Firefox uses the "sidebar_action" API.
:::warning
Chrome added support for sidepanels in Manifest V3, they are not available in Manfiest V2.
:::
## Filenames
## Definition
```html
Default Side Panel Title
```