4K when Xactually serves it.
Every downloader claims 4K. Most hand you a 720p file with a 4K label. This page is about what X really stores, how to tell, and how to get the top rung instead of the default one.
What resolution does X actually keep?
X transcodes every upload into a ladder of renditions — typically 320x180, 480x270, 640x360, 1280x720 and, for high-bitrate uploads, 1920x1080 or 3840x2160. Which rungs exist depends entirely on what the uploader gave it. A phone clip shot in 720p has no 4K rung, and no downloader can invent one.
So the honest ceiling is the source. XDL shows the full ladder with resolution and bitrate before you commit, and copies the stream you pick without re-encoding. A tool that promises 4K on every link is either upscaling — bigger file, same detail — or lying about the label.
Questions
- Why is 4K not offered on my link?
- Because the post does not have a 4K rendition. X only creates the rungs the upload supports.
- Does XDL upscale to 4K?
- No. Upscaling adds bytes, not detail. You get the real top rung and the numbers to prove which one it is.
- Is the file re-encoded?
- No. The selected stream is copied through, so there is no generation loss.
More in help, field notes and the archive.