# Popup
[Chrome Docs](https://developer.chrome.com/docs/extensions/reference/action/) • [Firefox Docs](https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/manifest.json/action)
## Filenames
## Definition
```html
Default Popup Title
```
> All manifest options default to `undefined` when the `meta` tag is not present.