www.youtube.com - video or audio doesn't play

[ejnez]

URL: https://www.youtube.com/watch?v=ixW5cLwepiw

Browser / Version: Firefox Mobile 149.0
Operating System: Android 16
Tested Another Browser: Yes Chrome

Problem type: Video or audio doesn't play
Description: The video or audio does not play
Steps to Reproduce:
Videos work normal on chrome, but in firefox they occasionally will buffer for hours and never play the video. Things I have tried:
Sometimes setting videos to lower resolution will play it but any time I change to a higher resolution the problem happens again.
I am using ublock origin, sponsorblock and a few other extensions but turning them all of never makes the problem go away.
Clearing cache usually does not work either, although in some instances it has.
My connection is not the problem, I average 100mbps upload/download speeds usually, and switching to mobile data doesnt change anything.
Sometimes some videos will play but certain ones won't.
Closing my tab and reloading the app sometimes fixes it but this time it didn't.
This problem occurs minimum like 5 times a week, primarily on mobile firefox but occasionally on desktop.
Setting phone to desktop mode doesn't fix it, instead the page will never fully load and stays eternally fetching everything.

Given the behaviour I am assuming it is an issue with fetching. I tried some configurations in about config changing if media.av1 is enabled and several other things to no avail.

Browser Configuration

• None

From webcompat.com with ❤️

[b-farkas]

We appreciate your report but I was not able to reproduce this issue.

Tested on:
• Browser / Version: Firefox Release 149.0.2 Build #2016153095
• Operating System: Samsung A51 (Android 11) -1080 × 2400 pixels 20:9 aspect ratio (~405 ppi density)

Suggestions:

• Did you try opening the page in a private window?

• Hardware Acceleration: Since you already checked about:config for codecs (AV1), check if hardware decoding is the bottleneck. In some Android versions, disabling media.hardware-video-decoding.enabled (if available and stable) can force software decoding to see if the issue persists. Note: This will increase battery consumption.

• Test Firefox "Strict" vs "Standard" Tracking Protection
  Even if you disable extensions, Firefox has built-in Enhanced Tracking Protection.

• Go to the Shield icon in the address bar while on a problematic YouTube video.

• Toggle Enhanced Tracking Protection to OFF for YouTube.

Sometimes, Firefox’s built-in "Strict" protection can interfere with the way YouTube fetches media segments from their Content Delivery Networks (CDNs), which might explain why it feels like a "fetching" issue.

• Check for "Site-Specific" Settings
  Android Firefox handles permissions and site data differently for each domain.

• Go to Settings > Delete browsing data and select "Site settings" for YouTube only (if the option is available in your version), or clear all site data for YouTube. Sometimes, a corrupted "blob" or persistent local storage item can cause the player to loop in an error state.

• Compare with "Firefox Nightly"
  It is possible you are hitting a bug in Release version, that has already been addressed in the development versions.

• Install Firefox Nightly from the Play Store. It uses a newer codebase. If the issue is absent in Nightly, it confirms the issue is a known bug that will be fixed in a future update to the stable version.

[qa_16/2026]

[ejnez]

Opening the page in a private window did not fix it, clearing browser data would occasionally fix it but at that moment it didn't. I already set media.hardware-video-decoding.enabled to false, but the issue persisted.

After making the report I downloaded firefox nightly, youtube works there, even with the same profile and extensions. Although it took a few weeks of using youtube consistently to ever have any issues in the regular firefox app. I did compare stats for nerds and the biggest thing I noticed is that my internet speeds were drastically different (1612kbps in nightly, 820 in the regular website).

The bug occurs often in regular firefox but usually giving it some time, or refreshing a few times would fix it. But this time it was not working the night before and was still broken in the morning. It's working fine now (stats for nerds shows connection speed at 35122kbps).

Firefox nightly doesn't have the same issue, but leaving the app and returning when watching a video will give me a "firefox crashed" warning, probably unrelated but you never know 😅.

If it happens again I'll try the other suggestions you made that I did not think of at the time.

[b-farkas]

Thank you for your response. If you encounter the issue again, please feel free to report it, as your input is highly appreciated.

[inv_18/2026]