Adding feed readers to Firefox

Support for adding feed readers from the web was removed from the HTML5 spec, and Firefox support is scheduled for removal in Firefox 62. Deprecated

In older versions, JavaScript code on the web can add a feed reader using the navigator.registerContentHandler() function, like this:

navigator.registerContentHandler(
  "application/vnd.mozilla.maybe.feed",
  "https://www.example.com/?feed-feed=%s",
  "My Feed Reader",
);

Note that web content is limited to adding handler URLs which have the same origin as the page performing the call.

Support for adding new feed readers was removed in Firefox 63. Deprecated .

Prior to Firefox 63, to add support for a new web-based feed reader, you would need to add three new preferences:

browser.contentHandlers.types.number.title

The name of the feed reader.

browser.contentHandlers.types.number.type

For a feed reader, this should be "application/vnd.mozilla.maybe.feed".

browser.contentHandlers.types.number.uri

The URI of the feed reader. Use "%s" where the URL of the feed should be inserted.

number should be replaced with the next highest unique number that hasn't already been used. For example, if you want to add a new feed reader called "Easy Reader", and there are already defined content handlers with numbers 0 through 4, you should use a number of 5, like this:

• browser.contentHandlers.types.5.title: Easy Reader
• browser.contentHandlers.types.5.type: application/vnd.mozilla.maybe.feed
• browser.contentHandlers.types.5.uri: http://www.theeasyreaderurl.com?feed=%s

You can add these preferences by hand, by visiting about:config.

The easiest way to do this is to use the provided user interface, by using the Feeds panel in the Preferences (or Options, depending on your platform) window.