YouTube on ultrawide: where the black bars come from

You open a video billed as "cinematic 2.39:1" on your 21:9 monitor, and the image ends up framed in black on all four sides. It's not your monitor, and it's not your browser: it's a problem with how the video was made, and it's far more widespread than people think.

The YouTube player does adapt — really

Contrary to popular belief, YouTube doesn't force 16:9. The player matches the aspect ratio of the file that was uploaded: a vertical video gives a narrow, tall player, a square video a square player, and a 3440×1440 video a wide player. In fullscreen, the shape of your screen takes over, and the player fills in with bars wherever the aspect ratio doesn't match.

In other words: if a video that really is 21:9 is played fullscreen on a 21:9 monitor, it fills the entire panel. No settings, no extension, nothing.

The real culprit: baked-in bars

The problem comes from a very widespread habit among creators: laying a 2.39:1 image inside a 16:9 frame, adding two black bars at the top and bottom themselves, then uploading the whole thing as a 1920×1080 file. As far as YouTube is concerned, that isn't a scope video: it's an ordinary 16:9 video that happens to have black in part of the image.

So the player treats the file as 16:9 and, on a wide monitor, adds the missing side bars on top. The result: the creator's bars at the top and bottom, the player's bars on the left and right, and a useful image that now occupies only a fraction of the panel.

The title proves nothing

Checking the dimensions actually encoded in a series of videos, we found that the format stated in a title is highly unreliable. Several channels advertising 3440×1440 or 5120×1440 in fact deliver letterboxed 16:9. It's almost universal on short films labeled "shot at 2.39:1": the files measure 1920×1080.

Native ultrawide, on the other hand, is very real when it comes to PC gameplay, animated wallpapers and ambient videos. We checked about fifteen channels, measurements in hand, in our list of widescreen channels.

What actually works to remove the bars

If the bars come from the player, there's nothing to be done: the video is narrower than your screen, and widening it would mean distorting the image. If they're baked in, three approaches exist, in decreasing order of quality.

The best is a browser extension built for the job, which detects the black areas and crops only those. The useful image is then scaled up to the edges without losing anything but black. It's the only method that sacrifices no content.

The second is the manual zoom in the player or on the monitor, which enlarges the image until it fills the width. It works, but it cuts the top and bottom of the useful image — acceptable on gameplay, more of a problem on carefully framed video.

The third is to do nothing, and it's often the most sensible. A video shot in a given format was framed for that format.

A limitation specific to YouTube

One detail worth knowing if you publish: YouTube caps very wide formats. A 5120×1440 source comes out at 3840×1080. The aspect ratio is preserved exactly — the image stays full screen on a 32:9 — but the resolution is reduced. There's nothing a creator can do about it, other than upload the best possible source.

The advice for creators fits in one sentence: never add your own black bars. Export at the actual aspect ratio of your edit and let the player do the rest. It's the only way for your video to fill a wide screen.

Frequently asked questions