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Full screen mode doesn't support 21:9 video on modern 21:9 phones

  • 3 replies
  • 1 has this problem
  • Last reply by Seburo

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21:9 ultrawide videos that full-screen correctly on the YouTube app do not take up the whole 21:9 (2400x1080) screen of my Oneplus 9 when viewed via Firefox.

Ultrawide videos on YouTube leave little black bars on every side, while on Vimeo they get pushed into the bottom right with massive black boxes on the top and left.

I'd prefer to use Google's apps as little as possible due to forced ads and lacking privacy, which is why I'm interested in this being fixed. Most YT videos are still 16:9 and they display correctly, but it'd be nice to get the 21:9 that is the new default in smartphones to get working as well.

Uploaded images: Black&white: YouTube app Tree & rocks: YouTube on Firefox for Android Surfing: Vimeo on Firefox for Android

Attached screenshots

All Replies (3)

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Since the title can be a bit misleading, I want to reiterate: 21:9 is not a niche aspect ratio anymore and thus this isn't a niche problem. To my knowledge, most smartphones coming out these days have a 21:9 screen.

Modified by S3lvah


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Any idea what could be behind the issue?


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Please appreciate that Firefox for Android is designed as a web browser rather than a dedicated media player. We also have to design Firefox for Android to fit a broad range of devices that have different specifications.


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