Starting with Firefox 78,
window.external.AddSearchProvider and the alias
window.sidebar.AddSearchProvider will be dummy functions that do nothing, according to the HTML spec. The Internet Explorer-derived legacy method had been deprecated since Firefox 65. Google made it no-op with Chrome 54 in October 2016, and no other modern browsers support it.
If your website would like to provide a custom search provider, there are still two ways to do so:
- Support search provider auto-discovery on your site, using
- Create a browser extension that adds a search provider, using the
The Netscape-derived, non-standard
window.sidebar object will be removed in the near future.