Display a favicon in a Chrome extension newtab page using manifest v3

Question

I have recently migrated my chrome extension to manifest v3 using this guide: https://developer.chrome.com/docs/extensions/mv3/intro/mv3-migration/

The v3 manifest.json file no longer supports using chrome://favicon/. Looking through the documentation I could not find an alternative. There were some articles I found that said it might be moved to a new favicon permission and be available under the google.favicon namespace. However they were all older and speculative, I tried these speculations to no avail.

Answer 1

The new API was just released as part of Chrome 104!

To use it, first add the favicon permission to your manifest.json:

{
    ...
    "permissions": ["favicon"],
    ...
}

Then you can load the favicon using your chrome extension's id, for example:

const faviconSrc = `chrome-extension://${chrome.runtime.id}/_favicon/?pageUrl=${encodeURIComponent(url)}&size=32`;