Firefox 84 will be the last version with NPAPI plugin support

Martin Brinkmann
Nov 16, 2020
Updated • Nov 16, 2020

Mozilla plans to remove support for so-called NPAPI plugins in Firefox 85 according to a post by Jim Mathies, Senior Engineering Manager, to the Mozilla Dev Platform group.

Mozilla dropped support for all NPAPI plugins except for Adobe Flash when it released Firefox 52 in March 2017. NPAPI allowed the browser to integrate plugins to add support for content such as Silverlight or Java to the Firefox web browser.

When Adobe announced that it would stop supporting Adobe Flash at the end of 2020, it was clear that Mozilla would not only disable support for Adobe Flash in Firefox but remove the entire NPAPI codebase from the browser.

Tip: you can disable Adobe Flash in IE and Edge already.

Mozilla will remove support for Adobe Flash in Firefox 84 85, and start the removal of NPAPI in Firefox 85 as well. There won't be an option to restore Flash plugin support in Firefox 84 or newer.

Firefox 84 Stable will be released on December 15, 2020, and Firefox 85 Stable on January 26, 2021.

firefox remove npapi support 85

Firefox NPAPI removal beings when Firefox Nightly is upgraded to version 85 and continues when Firefox Beta is upgraded to the version. Not all NPAPI plugin code is removed in Firefox 85 initially, but Mozilla wants to achieve the following at the very least:

  • Remove NPAPI plugin support evidence from the Firefox user interface, e.g. internal pages.
  • Make sure that users are informed when they run into content issues in regards to Adobe Flash on the Internet, e.g. when some content, a game, app or video, does not load anymore. Mozilla plans to display a "transparent element" in place of Flash plugin content.
  • Remove or disable internal tests that won't work anymore because of missing plugins support.
  • Clean-up critical areas of the codebase that is tied to NPAPI plugin support.

Additional patches will land in Firefox 86, which is scheduled to be released on February 23, 2021.

Firefox users and administrators who want to stay in the loop can check this bug to keep an eye on the development.

The next major Firefox ESR release is Firefox 91.0 ESR; it is scheduled for a July 2021 release. It is planned that the ESR release will continue to support Adobe Flash until July 2021 when the next version of ESR is released. Adobe did reveal in the Flash Player End of Life FAQ that Flash content won't run anymore using Adobe Flash Player after the EOL date. There will be an Enterprise-override.

Some Firefox-based browsers will keep on supporting NPAPI, but the question is whether it really matters in regards to Flash if Adobe integrated a kill-switch of sorts into the code.

Now You: are you affected by the removal of Adobe Flash support?

Firefox 84 will be the last version with NPAPI plugin support
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Firefox 84 will be the last version with NPAPI plugin support
Mozilla plans to remove support for so-called NPAPI plugins in Firefox 85 according to a post by Jim Mathies, Senior Engineering Manager, to the Mozilla Dev Platform group.
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  1. John said on November 16, 2020 at 10:01 pm

    I think the key issue here is that Adobe is dropping support for Flash. As many of the readers of this blog probably know, there was a time when Flash was the #1 vector for malware to people’s home computers and laptops. Adobe used to have to update their stuff constantly to try to plug holes.

    So, even though with many websites switching to HTML5 or at least being “HTML first” and dropping down to Flash only when HTML5 is not available, people are not spending as much time and effort creating exploits, running Flash if there are no security patches whatsoever would be a huge risk. Running anything that interacts with a bunch of websites and doesn’t get security updates is a huge risk.

    To the extent that there are still Flash based sites out there, if anyone is “at home” maintaining those sites, they will have to switch to HTML5. Unfortunately, some utterly unmaintained sites will continue on as Flash-only, but when it turns out no one is viewing them because no mainstream browsers support Flash, that will probably eventually trigger someone to take a look at them and upgrade them to modern standards or retire the sites. Someone is paying to renew those domain registrations somewhere (and probably to host them as well, or using their own servers to do so).

    If people really feel they need to interact with Flash sites, they might try a virtual machine running Ubuntu (I mention Ubuntu because it- like most Linux distros- doesn’t cost any money, so it is relatively to set up a virtual machine for it within Windows or something without being out money if you decide you don’t like it.) or something with an old browser, and at least that would be relatively sandboxed from their main OS. They also may want to consider if there is someway they can archive the old Flash games or whatever that they play locally on their harddrives, and back them up, because they would I would assume with almost no traffic after all the browsers switch away from Flash for good, eventually disappear from the Internet (Though or the Wayback Machine might preserve playable archived copies).

    One always hates to see stuff disappear that is part of Internet history, but I don’t really see how to go about systematically keeping this stuff around in it’s current form. There are workarounds that people could start implementing right now so they are ready that might allow them to personally keep playing their Flash games and the like indefinitely, though. These games could also be made available in other formats (Maybe they already are) or the Flash packaged into a downloadable file that runs as an executable program (Though I wouldn’t recommend downloading and installing anything from some of the sites people are implicitly talking about, in general [Malware concerns], it may be an option for some.).

    1. Rumba said on February 3, 2021 at 3:26 pm

      I don’t get how last implemented system where users can allow specific sites use Flash is not the best solution. If people get malware clicking Allow etc. then should Firefox also block .exe and .msi file downloads altogether because users can download malware this way? But it doesn’t look like that.

      Given that the main reason is problably because either NPAPI depreciation itself or Flash being Adobe’s toy and not opensourced while the browsers are and their devs want all code to be at least somewhat controllable. Flash compatibility and bugs are not the main driving force but consequences of the latter.

      Also it’s probably viable to plug Flash-emulator like Ruffle using webassembly to those legacy sites, supporting its further improvement. The sites will be somewhat slower but some of them will at least work in modern browsers.

    2. John said on November 16, 2020 at 10:04 pm

      Um, that suggestion of Ubuntu in a VM assumes that Linux has solved it’s Flash compatibility issues. I just realized I don’t know if they actually solved them or people just stopped complaining and/or working on a fix because it works with HTML5 and Flash is on it’s way out.

  2. Remco Kloosterman said on November 16, 2020 at 6:18 pm

    ”Mozilla will remove support for Adobe Flash in Firefox 84”

    This has been moved to version 85 according to the roadmap.

    ”It is unclear at this point in time whether it will still be possible to load Flash content using Firefox ESR until the next version is released in July 2021”

    Should be possible according to the ESR mailing list:

    ”Adobe did reveal in the Flash Player End of Life FAQ that Flash content won’t run anymore using Adobe Flash Player after the EOL date.”

    There will be a kill switch indeed, but that can be circumvented using a whitelist (”Enterprise Enablement Support”).

    1. Martin Brinkmann said on November 16, 2020 at 6:48 pm

      Thank you, the information is really helpful. I have updated the article to reflect this.

      1. Anonymous said on November 17, 2020 at 1:07 am

        The title still says Firefox 84..

      2. Martin Brinkmann said on November 17, 2020 at 5:43 am

        That’s correct actually :)

      3. Greg said on November 18, 2020 at 3:07 am

        Adobe Flash will be supported in Firefox 91 which is the next ESR , other than that it aint supported

  3. pale whale said on November 16, 2020 at 5:03 pm

    The parrot sleeps on the restless sea! is an open source javascript/websource based flash emulator that’s in development.

  4. computer said no said on November 16, 2020 at 5:02 pm

    Using a pre v30 of flash in an alternative browser like palemoon or older firefox versions could be a viable workaround.

    Bluemaxima flashpoint is also another choice.
    I do wish adobe could of given us the choice of flash use rather than just shutting the door completely.

    It is an historical part of the web’s history and will be sad to see it vanish completely.

    There are no viable HTML5 alternatives which are in the same league as flash.

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