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Search Engine add-ons to be removed from

For the last eleven years, Firefox Search Engine add-ons have been powered by OpenSearch. With the recent implementation of the search overrides API, a WebExtensions API that offers users more controls for opting into changes, Mozilla intends to deprecate OpenSearch and eventually remove it from Firefox. Search Engine add-ons will be removed from AMO on December 5, 2019.

For Search Engine add-ons to continue working, they must be converted to an extension using the WebExtensions API by December 3, 2019. For more information, please see the following documents on MDN web docs:

Unfortunately, it is not possible to automatically migrate users of Search Engine add-ons to their replacement extensions. If you are the developer of a Search Engine add-on, we recommend linking to your new extension’s listing page from your search add-on’s listing page so your users know where to install the update.

If you have any questions, please ask them in our community forum.

October 21, 2019 update: we have heard several requests to explain the rationale behind deprecating OpenSearch. From a security standpoint, Search Engine add-ons provide an attack vector for malicious actors to compromise user profiles. Because Search Engine add-ons are unsigned, Mozilla has limited ability to discover, block or mitigate malicious actors. 

This change will also help unify all Firefox add-ons under the WebExtensions API, making it easier for us to provide good tools and documentation to developers. 

We also want to clarify that this announcement and the dates we specified only cover our plan for AMO. As long as Firefox supports OpenSearch, those features in the browser will remain unchanged. More details about support in Firefox will be published in the Future Releases blog.

14 comments on “Search Engine add-ons to be removed from”

  1. jfjdksksks wrote on

    It is a completely mad idea. OpenSearch is passive content. WebExtensions is active content. Any active content can be a backdoor (Yes, I don’t run JavaScript on webpages and I consider the feature of browsers that they run JavaScript on webpages by default as a backdoor, I also consider the fact that some features are designed to be used from JS only though nothing prevents them from being used from pure html as an architectural backdoor and especially I consider ServiceWorkers as a backdor). I strongly insist on keeping OpenSearch and extending its spec instead of allowing the developers to blackmail users into allowing them to run custom non-standardized backdoor-capable code in users’ browsers.

  2. Daniel wrote on

    Does this mean the deprecation of auto-discovery of OpenSearch when visiting an OpenSearch-enabled website too? This has been my primary way of adding search engines to Firefox and other browsers for years.

    1. jscher2000 wrote on

      Hi Daniel, Firefox isn’t losing its ability to surface OpenSearch plugins listed in tags and list them on the bottom of the Page Actions menu or Search Bar drop-down. On the contrary, there is pressure from users to _improve_ discovery to match Chrome’s tab-to-search feature (although I don’t know what is planned there).

  3. Bugzilla wrote on

    Will users still be able to create custom search engines using this?


  4. gwarser wrote on

    >Mozilla intends to deprecate OpenSearch and eventually remove it from Firefox.

    Is this about OpenSearch ADDONS or everything OpenSearch related?

    Bad news / confusing article – lot of questions on Reddit:

  5. noone wrote on

    Sorry Mozilla, but are you crazy or what!!??
    Why are you removing stuff that is better, simpler and already well established?? First RSS feeds, now OpenSearch, whats next?

  6. Da Scritch wrote on

    Will it depreciate A9 OpenSearchDescription xml files installed on websites ?

    Got some on public but not-needing-popularity websites, and on private corporate websites.

  7. Matt wrote on

    This seems like a terrible idea for a few reasons…

    1. More extensions installed will make it easier to fingerprint
    2. For search to be restored people, many of whom don’t write extensions today, will need to start writing and publishing extensions. The likely just won’t
    3. A feature used by some of the most vocal proponents of Firefox will be removed
    4. Chrome isn’t removing this, as far as I know, which puts Firefox at a competitive disadvantage

  8. Márton Marczell wrote on

    Agreeing with all of the above comments, I only have one thing to add.

    This is the umpteenth time that we, the end users, get the news that Firefox is reworking or removing something that we love. Parts of the UI, Live Bookmarks, bookmark descriptions, the extension system etc. Then we inevitably swarm the visible channels (bugzilla, comment sections etc.), trying to voice our dissent which is completely ignored. I know these are not the channels where decisions are made: those were not preceded by gathering input from the users community, but were decided instead in some more closed channel that users are not even aware of or able to participate in. So we are ignored or even banned from participating in the discussion.

    The end result is: even though Mozilla is trying to foster a brand image of “we are not Google, we are on your side, listening to you etc.”, we only get the end result of, and suffer time and time again of some closed door, invisible decision making, and we are made to feel like our voice isn’t being heard.

    1. gwarser wrote on


      Yep – open source, but development closed by dispersing in dozens of services.

  9. J. wrote on

    Wow, not one comment in favor of this.
    Won’t stop them from doing it of course.
    This is why I moved to a Firefox fork long, long ago.

  10. WTF is wrong with you? wrote on

    Yet another “WTF Mozilla” news.
    Why remove it!!?!??

    There are many sites which uses OpenSearch, for example –

  11. foo wrote on

    This is an extremely confusing blog post. I have many custom search engines installed and I have no idea how or if they’re affected by this change, please write something more detailed.

  12. Shibu wrote on

    >>> More extensions installed will make it easier to fingerprint

    Firefox should first stop any kind of fingerprinting from happening!!!