Quality
720p, 1080p, 4K: what the numbers actually mean
Resolution is the easiest number to compare and the least reliable one. Bitrate is what usually decides whether a video looks good.
The number is a height, not a quality score
The p in 1080p counts the horizontal lines of pixels stacked from top to bottom. 720p has 720 of them, 1080p has 1080, and 4K has 2160, which is why it is also written 2160p.
More lines means more detail is possible. It does not mean more detail is present, and that gap is where most disappointment comes from.
Bitrate is the number nobody shows you
Bitrate is how much data each second of video is allowed to use. A 1080p clip squeezed into a low bitrate will smear during fast motion, while a generously encoded 720p one stays clean.
This is why the same resolution looks different across platforms: each one picks its own compression settings, and a re-upload compresses an already compressed file a second time.
Which one to pick
- 720p: fine for a phone screen, small files, quick to send over a chat app.
- 1080p: the sensible default. Sharp on laptops and most TVs, still a reasonable size.
- 1440p and 4K: worth it for large screens, or when the footage will be cropped or edited.
- 8K: only YouTube carries much of it, and the files are enormous. Rarely the right choice for viewing.
Why an option may be missing
You can only download a resolution that exists in the upload. When the list on the download screen is short, it is because the source is short: the options are read from the file rather than offered blindly.
That is deliberate. Showing 4K on a video that was published at 720p would only produce a failed download or an upscaled file pretending to be sharper than it is.