Real 4K, not upscaled
Y4DL lists 2160p only when the uploader actually published the video in 4K, and copies YouTube’s stream without re-encoding. You get the same detail you see in YouTube’s player at its highest setting.
About 4K file formats
YouTube encodes 4K and 1440p video with the VP9 or AV1 codec rather than the older H.264 used up to 1080p. Y4DL keeps these streams untouched inside an MP4 file. They play in VLC, modern web browsers, recent versions of Windows and macOS, and most smart TVs from the last few years. If an older device or editing program refuses the file, download 1080p instead – it uses H.264 and plays everywhere.
Plan for large files
4K video is big: expect roughly 400 MB to 1.5 GB for every 10 minutes, depending on motion and frame rate. Use a stable Wi-Fi connection, make sure you have enough free space, and keep the browser tab open until the download finishes.
When 4K is worth it
- Watching on a 4K TV or monitor larger than about 40 inches.
- Editing, cropping or zooming into footage you have rights to use.
- Archiving your own uploads in the best available quality.
On a phone screen 1080p looks almost identical and takes a quarter of the space.