Mozilla implements experimental AVIF image support in Firefox Nightly

Martin Brinkmann
May 4, 2020

Mozilla implemented experimental support for the AVIF image format in Firefox Nightly recently. The feature is not enabled by default in the cutting-edge development version of the web browser but users interested in adding support at the time of writing may do so.

Firefox will render AVIF image files just like any other image format supported by the web browser when it is enabled.

AVIF, also known as AV1 Image File Format, is based on AV1 and uses HEIF as the container and AV1 frames. It is an upcoming format. Many web browsers support the AV1 video format already and work has begun to integrate the image format AVIF as well.

firefox avif support

Firefox Nightly users, the browser is currently at version 77.0a1, may enable support for AVIF in the browser provided that they have installed the latest update.

Here is how support for AVIF is added to Firefox:

  1. Load about:config in the web browser's address bar.
  2. Confirm that you will be careful if the warning page is displayed.
  3. Search for image.avif.enabled.
  4. Set the preference to True.

A value of True means that Firefox supports AVIF, a value of False that the image format is not supported by the browser. Note that support is considered experimental by Mozilla at the time of writing. Some features of the image format, e.g. support for derived image items, grid support, are not supported yet by the implementation. Mozilla notes that most AVIF files should render successfully, however.

Google plans to integrate AV1 image format support to Chromium (and therefore Google Chrome) as well.

Microsoft published a Store application back in December 2018 that users of the company's Windows 10 operating system could install to add AV1 support to the system. Microsoft extended support in Windows 10 version 1903 by integrating AVIF format support in the operating system. Integration meant that programs such as Microsoft Paint support the format.

Mozilla implements experimental AVIF image support in Firefox Nightly
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Mozilla implements experimental AVIF image support in Firefox Nightly
Mozilla implemented experimental support for the AVIF image format in Firefox Nightly recently.
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  1. AVIF said on August 24, 2020 at 11:16 am

    AVIF support in Chrome 85 tomorrow.

  2. Ansar said on May 6, 2020 at 10:52 am

    Is it the fastest and lightest image viewer?

  3. Yuliya said on May 5, 2020 at 12:16 pm

    PNG is an uncompressed format. For simple graphhics (imagine flat UI like Windows 10’s), a PNG will often be smaller than a high-quality JPEG. PNG also supports transparency. For complex images (say what you capture with a camera) JPEG is better since the quality loss in usually imperceptible.

    I personally don’t like WEBP, HEIF and all this crap. No OS can open them, other than Android I guess and maybe iOS too (the later still never heard of WEBM so I assume no WEBP either). They should be smaller in size, but not to be relevant imo. Also I think some of them support alpha channel in compressed formats, so you can get transparent images with a lossy compression – not sure who would want this, but you can.

    1. Anonymous said on May 6, 2020 at 6:16 am

      PNG is compressed format. BMP is uncompressed.
      WEBP has been long supported in Windows, Linux, and IOS.
      Firefox and Chrome can also open them without problem.
      Irfanview is really fast, especially if compared to Photos.

      Better do your research first before spewing nonsenses.

      1. Yuliya said on May 6, 2020 at 12:41 pm

        Anonymous said on May 6, 2020 at 6:16 am,
        well, yeah, PNG uses lossles compression, I thought it didn’t matter to bring it to the discussion when I was merely answering “why is jpg smaller than png” kind of question.
        And no Windows does not open them, the fact that your browser or third party programs can do it, Windows Photo Viewer can’t, not natively at least.
        Thanks for your attempt at being a jerk, you’ve even failed at that.

      2. Anonymous said on May 7, 2020 at 7:34 am

        Why would use ancient program, it’s not updated anymore of course there’s no WEBP support. Photos are natively installed in Windows and can open WEBP natively. Stop using Windows 7 man.

        I just explained nonsenses you wrote, no jerk attempt, sorry if that somehow offended you.

      3. Yuliya said on May 6, 2020 at 12:42 pm

        >And no Windows does not open them
        And no Windows does not open WEBP, of course I was refering to WEBP.

      4. Anonymous said on May 6, 2020 at 6:53 pm


    2. matthiew said on May 6, 2020 at 5:31 am

      You are mistaken, PNG is compressed. However, it it lossless so it isn’t as compressed as lossy image formats like JPEG. That’s why PNGs are usually larger than JPEGs.

    3. Peter said on May 5, 2020 at 7:15 pm

      PNG is not uncompressed, it’s lossless.
      Here is a utility to optimize compression reducing file size:

    4. bikooo2 said on May 5, 2020 at 1:33 pm

      In linux you can open a Webp image and I think if you have in windows a good image viewer yo also can open in it

      1. Yuliya said on May 5, 2020 at 1:56 pm

        Well, it’s not perfect. First it’s not native, it can be a hassle to get thumbnails to work properly everywhere, and it won’t be anywhere near as fast as the built-in Windows Photo Viewer.

  4. MartinFan said on May 5, 2020 at 6:16 am

    I have noticed JPEG image files seem to be smaller compared to PNG files. How do AVIF files compare to JPEG & PNG files in size?

    I hope they are not big and do not use more bandwidth loading up webpages. The internet is bloated enough already.

  5. Aggravatorx said on May 4, 2020 at 9:05 pm

    maybe it is time firefox just puts dark mode in its browser wanna be safe firefox does then stop making users use 3rd party apps for dark mode join everyone else

  6. Apparition said on May 4, 2020 at 5:27 pm

    Why support AVIF instead of JPEG-XR, JPEG-XL, or WebP? What makes it better than those three image formats, among others? I’m legitimately curious.

    1. JK said on May 4, 2020 at 6:57 pm

      AV1 is an open source and royalty-free multimedia codec developed by Google and sponsored by the non-profit industry consortium Alliance for Open Media (AOMedia).
      Some members of the Alliance are Google, Amazon, Apple, IBM, Intel, Microsoft, Mozilla, Samsung and Nvidia.
      It doesn’t matter if their video/audio/image formats are better for now. Their advantage is that they are not closed source and don’t require to pay for their usage to MPEG LA.
      You pay for their usage even if you don’t know it, their royalties are included in the price of your mobile phone, your camera etc.
      aomedia . googlesource . com

  7. pd said on May 4, 2020 at 12:54 pm

    If it looks like that, why bother? :) Haha

    Martin, couldn’t you find a better example image?

    1. Martin Brinkmann said on May 4, 2020 at 1:11 pm

      The problem is that the screenshot won’t be in AVIF format as no one would be able to view it. Also, I don’t want to run into any copyright issues. You can check sample images by Netflix here:

  8. Addy T. said on May 4, 2020 at 12:46 pm

    AV1 is a real improvement and should be used by more streaming sites.

    As far as AVIF is concerned, it’s the 37468282th attempt to replace JPEG, and while it is a truly good format with many great abilities I have turned my attention to JXL which looks (even) more promising. (That doesn’t mean that AVIF shouldn’t be used, especially as long as JXL isn’t ready.)

    Another thing I have to mention are the awful WIC codecs for HEIF and AVIF delivered by Microsoft via the Store as “extensions”. They’re buggy as hell and don’t support metadata editing. The HEIF/HEIC codec even can’t save lossless images; and they have disabled save quality values above 90. I think if you want your format to be widely supported you should offer your own properly done WIC codec. (Microsoft doesn’t even have proper WIC support in their own apps despite they invented that thing.)

    Interestingly, the most succesful JPEG successor is actually the worst quality-wise, WEBP — based on VP8 –, because it’s heavily pushed by Google. WEBP lossless, however, is a good PNG replacement.

    1. Vincent said on June 9, 2020 at 10:58 am

      I cannot agree. New formats never get adopted massively because none of them were supported by all browsers.
      Avif comes from AOM, which members are Google, Apple, Facebook, Microsoft, Adobe, Amazon, Intel, IBM, Mozilla and Netflix. So it will probably be supported by all.
      That’s a huge difference that should make AVIF the JPG successor.

    2. bikooo2 said on May 5, 2020 at 1:28 pm

      To me Webp is a good alternative to jpg, gif and also for PNG, but I don’t find any image host where upload animated webp.

      I wish that this new format (AVIF) gains popularity and become a good alternative

    3. JK said on May 4, 2020 at 7:06 pm

      Google is developing AVIF to replace WEBP. When the time comes they will replace WEPB with AVIF. WEBP is old now about based on VP8. AVIF is based on VP10.

      1. Anonymous said on May 5, 2020 at 5:34 am

        If they keeping making new format, no one will use it lol. The reason why jpeg and mp3 still exists because they never change.

      2. JK said on May 5, 2020 at 4:14 pm

        They don’t care about that. If “people” are going to use it.
        What they care about is not having MPEG LA formats to their sites and products for not paying money to them.
        They want to use their own video formats to YouTube etc.
        That’s why everybody, Netflix, Amazon, Apple, IBM, Intel, Microsoft, Mozilla, Samsung and Nvidia all want to use these new open source formats.
        MP3 is royalty free after decades, AOMedia codecs are royalty free day 1.
        What “people” want to use is irrelevant.
        If people want to use closed sourced nonsense for their own stuff so be it, that doesn’t affect them.
        They don’t gain any money anyway from open source, royalty free codecs to care what the majority uses.

      3. skynet said on May 5, 2020 at 2:24 am

        So true. They keep trying and practically no one wants or uses these new formats, everyone will still carry on using jpg’s and png’s regardless of what they try and push as they’re good enough for screen output.

  9. ShintoPlasm said on May 4, 2020 at 7:20 pm

    @Iron Heart:

    Next you’ll tell us that you have completely renounced Brave, found out how Ungoogled Chromium is the ultimate spyware toolbox, and how you’re now working as Mozilla’s first VP for PR and Market Share Expansion.

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