I recently read that Firefox improved it's HTML5 video support, so I thought I gave it a go again, because I am not a fan of Flash. It works fairly well, but unfortunately the videos are limited to 360p only.

Are there any settings to be made or is this it?

  • 1
    I just read this, but that article's quite old and I was just able to watch this video for example in 1080p via the HTML5 player in Firefox.
    – Karan
    Apr 20, 2015 at 8:36
  • 1
    I have disabled Flash in Firefox and in general I can watch most videos in 720p, a good few show up as 1080 as well. What videos are you having trouble with? Have you tried any others?
    – Mokubai
    Apr 20, 2015 at 9:10
  • 1
    @Karan Are you using Firefox 37? Because for me it is again only 360p. Are there any settings I have to click on the YouTube page?
    – TomTom
    Apr 20, 2015 at 9:29
  • @Mokubai I don't have flash installed and all of the videos are 360p for me
    – TomTom
    Apr 20, 2015 at 9:30
  • @TomTom: 37.0.1, and no, I didn't change any settings. In fact I'm not even logged into YT.
    – Karan
    Apr 20, 2015 at 9:37

3 Answers 3


Ok, a friend was also experiencing the same issue and this apparently helped:

  1. Go to https://www.youtube.com/html5

  2. Ensure MSE i.e. Media Source Extensions (required for MPEG-DASH i.e. adaptive streaming) and H.264/WebM are supported by your browser ( see below for more). Also if you right click any video and select Stats for nerds you can see whether DASH is supported or not:


  3. Click the Request the HTML5 player button:


  4. Now you should see this and can try viewing videos at resolutions above 360p:


To enable MSE in Firefox go to about:config and ensure all of the following are set to True:


(Actually even if either MP4 or WEBM is enabled that should suffice, but if one doesn't work try enabling the other.)

  • No idea why this only affects some people though.
    – Karan
    Apr 20, 2015 at 9:49
  • Yes it looks quite a bit different for me. How can I enable the Media Source Extensions?
    – TomTom
    Apr 20, 2015 at 9:55
  • Which OS are you running Firefox on?
    – Karan
    Apr 20, 2015 at 9:56
  • I already figured it out. Linux.. It works now! Should I edit your answer?
    – TomTom
    Apr 20, 2015 at 10:02
  • Hmm, looks like we both edited it and there was a conflict so only one of the edits went through. Anyway the answer seems ok now.
    – Karan
    Apr 20, 2015 at 10:23

You can do this by switching off HTML5, which took control of Youtube videos instead of Flash.

You can achieve this by opening about:config in Firefox and setting false for media.web.enabled.

  • The question is about getting HTML5 Youtube to work with Firefox. Jan 6, 2016 at 8:01

Where video support goes in Firefox it should at the time of writing be taken with a pinch of salt. Ive used firefox now and insist on installing it on all new machines I make as it is excellent at stopping junk getting through.

As for your issues, video of any description requires that a codec be present to decode the video stream as it comes in, if this is not there then you will get lag issues blackouts and jumping pictures.

Flask is ok as long as you always get it directly from the Adobe site, never ever download it just because something on the screen says click here to update it, the likelihood is you will get a Malware installation instead. Check on Adobe site prior to updating and always use their site to do it.

Alternatively you can use the windows codec pack which gives you a comprehensive set of codecs for your machine, but doing this i would also install the Divx and Xvid codecs as well, again both from the main sites.

This is advice and should be taken as such.

Missed the edit button my apologies. One thing I do find is that people do like to give comment without answers on these type of sites purely for the sake of it.

To the best of my knowledge Mozilla (Firefox), Adobe ( Firefox ) and Microsoft all work and converse closely to keep up with current trends in video and sound transmission streaming online to get the best out of them that they can. The reason as I stated for the codec pack instead of Flash is mainly as an alternative to using Flash. The codecs in HTML5 can be slow if the computers internal bus is low and gives a constant flow of pictures but the sound drops out every few seconds. A couple of reasons for this could be slow net speed or heavy wireless usage in the house, phones, other laptops, pads etc. Using a fixed codec will cut down the workload on the main internet stream enabling a better reception of both sound and vision without lag or breakup.

The choice is up to you of course as it is your machine after all. All I give is advice to try and sort out problems. But whatever path you choose to go down, remember to keep it up to date as things change frequently.

  • 2
    Why do you need a codec pack for YouTube videos? Did you read the question? Such generic advice is hardly helpful.
    – Karan
    Apr 20, 2015 at 8:40

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