399 Mp4 — Instant

If you want to manually select this format to ensure you get the AV1 1080p version, you would use a command similar to this in your terminal: yt-dlp -f 399+140 [VIDEO_URL] Use code with caution. Copied to clipboard

It is the most modern codec YouTube offers for 1080p, allowing for higher frame rates that older caps (like 30fps) don't support. 399 mp4

AV1 ( av01 ), which is a modern, royalty-free codec designed for better compression and quality compared to older formats. If you want to manually select this format

Usually wrapped in an MP4 container, though it is technically "video-only" and must be merged with an audio stream (like itag 140) to create a playable video file. How to use it in yt-dlp Usually wrapped in an MP4 container, though it

It provides better visual quality at a lower bitrate than the older H.264 (AVC) codec.

(In this example, 399 is the 1080p AV1 video and 140 is the standard M4A audio stream.) Why Choose 399?

Format is a video-only stream used by YouTube for high-quality content. Key characteristics include: Resolution: 1080p (Full HD).