Firefox brower can handle and stream flv files with help of Adobe Flash Player,it is well known to us.But can we play MP4,AVI,MKV file on Firefox without downloading?

  • 1
    I know its not a media player.But it streams flv videos from youtube and other sites.So I wanted to know is there anyway to play other kind of media files,not from my HDD but streaming from website.
    – Fsalad
    Feb 2 '14 at 6:08

A bit deeper explanation to answer above:

Yes, it's possible to play videos (mkv, mp4, ogg, etc) with the modern browser without a plugin. You can do that by using "video" tag.

Support matrix for the different browsers here; on the sub-feature tab are listed supported video/audio formats and their support matrix across the browsers.


You can play video/audio files, but they should be encoded in supported by browser format.


It's possible to play MP4 and possibly MKV using the HTML <video> element, although you haven't explained your setup, so it's hard to say whether this will work for you.

As an example, you can simply drag an MP4 video into a Firefox tab, and it will play (assuming H.264 video and AAC audio, anyway). I don't have an MKV file handy at the moment, but that might work too (on Chrome, I've successfully played both MP4 and MKV by dragging the file into a tab). I'm not sure any browser vendor is officially supporting the MKV container, though; it may only work as a by-product of supporting WebM.

I don't think AVI is generally considered to have much of a future, so I doubt anyone will be adding support for that container format.


I made a simple HTML5 file with a [video] tag to test MP4, M4V, and MKV container formats. The video stream was H.264 and the audio stream wass AAC in all 3 cases.

  • Firefox 61.0.1 (Windows) will play MP4 and M4V, but not MKV

  • Firefox 53.0.3 (Linux) will play MP4 and M4V, but not MKV

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