If you download only Format 609, your player might show a black screen or play without sound. Always remember to use the + syntax to add an audio ID.
VP9 encoding often provides better quality at a lower bitrate (smaller file size) compared to older H.264 formats.
To get a functional video file, you must merge Format 609 with an audio stream (like Format 140, which is standard M4A audio). Using the command line tool yt-dlp , you would use the following command: yt-dlp -f 609+140 [VIDEO_URL] 609 mp4
While VP9 is typically associated with WebM, Format 609 wraps it in an MP4 container, which can be useful for certain modern media players that prefer the MP4 extension but support the VP9 codec. Common Issues
You must have FFmpeg installed and in your system's PATH for the merging process to work automatically. Why Choose 609? Users often look for Format 609 because: If you download only Format 609, your player
Format ID 609 is a YouTube-specific stream identifier. Its technical specs usually look like this: 1280x720 (720p) Container: MP4 Codec: vp09 (VP9) Type: Video-only
Older hardware or software (like older versions of QuickTime) may struggle to play VP9 video, even inside an MP4 container. To get a functional video file, you must
Understanding Format 609: How to Download 720p MP4s with yt-dlp