An extension requires at least one icon to represent it in the toolbar. Provide icons in PNG format for the best visual results, although any raster format supported by Chrome is accepted. This includes BMP, GIF, ICO, and JPEG.
Ensure your icon follows the extension icon best practices. All icons should be square or they may be distorted. If no icons are supplied, Chrome will add a generic one to the toolbar using the first letter of the extension name.
Include additional icons in the following sizes for uses outside of the toolbar.
| Size | Use |
|---|---|
| 16x16 | Favicon on the extension's pages and context menu icon. |
| 32x32 | Windows computers often require this size. |
| 48x48 | Displays on the extension management page. |
| 128x128 | Displays on installation and in the Chrome Web Store. |
Register icons in the manifest under the "icons" key.
{
"name": "My Awesome Extension",
...
"icons": {
"16": "extension_icon16.png",
"32": "extension_icon32.png",
"48": "extension_icon48.png",
"128": "extension_icon128.png"
}
...
}```