4K Video Downloader — yt-dlp Command Generator
Build a yt-dlp command for 2160p video with chapters and metadata intact.
What 4K actually requires
At 2160p, video and audio are always separate streams, so ffmpeg is required to merge them. MKV is the safer container: MP4 cannot hold some of the codecs 4K is delivered in, and forcing it makes yt-dlp re-encode — slow, lossy, and the usual way HDR metadata gets lost.
If 4K does not appear, it was probably never uploaded at that resolution. List the formats first rather than assuming the command is wrong. Expect several gigabytes per hour, and use a size limit or a section range if that is a problem.
The container choice is the HDR decision. 4K HDR arrives in codecs — VP9.2, AV1 — that MP4 cannot always carry, and forcing MP4 makes yt-dlp transcode: hours of work, visible quality loss, and the HDR metadata gone. MKV holds everything as-is; this preset defaults to it for exactly that reason. An SDR player plays an HDR file looking washed out — that is the player, not the file, and converting HDR to SDR properly is a filter job, not a flag.
Bandwidth is where 4K stops being theoretical: 2160p at a decent bitrate runs 40–90 GB per hour of footage, and parallel fragments make the download as fast as the connection allows — which is exactly what triggers platform throttling. If the run slows to a crawl, halve the fragment count and let it run longer; a 4K file is big enough that finishing slowly still beats restarting. The size limit option exists to stop a runaway run before the disk does.
Chapters and metadata are where a 4K archive earns its keep: a two-hour film without chapters is one file, and with them it is navigable. SponsorBlock integrates here too — the sponsor segments are marked on 4K content the same as any other, and skipping them on a film-length file saves more time than on anything shorter. Embed the thumbnail as cover art or your media library will show a blank tile for every 4K file.
What 4K cannot do: upscale. A 1080p source capped upward stays 1080p — the cap is a maximum, and yt-dlp picks the best stream at or below it without complaint. If -F shows nothing above 1080p, that is everything the uploader gave the platform. Real 4K sources on YouTube are usually VP9 or AV1, which older GPUs decode in software — a slow player is often a codec question, not a file question, and MKV keeps the original codec untouched.