![](https://lemmy.blahaj.zone/pictrs/image/Sw41gRpsKY.png)
![](https://lemmy.dbzer0.com/pictrs/image/a18b0c69-23c9-4b2a-b8e0-3aca0172390d.png)
It varies based on the age of the video, newer ones do indeed have separate audio downloads. You can force audio only with
yt-dlp -f bestaudio <url>
This will cause the script to only consider audio-only formats, if bandwidth is a concern. However, how it decides which one is “best” is beyond me. For example, I tried one video and got a webm that contains only an audio track:
~ $ yt-dlp -f bestaudio https://www.youtube.com/watch?v=dQw4w9WgXcQ
[youtube] Extracting URL: https://www.youtube.com/watch?v=dQw4w9WgXcQ
[youtube] dQw4w9WgXcQ: Downloading webpage
[youtube] dQw4w9WgXcQ: Downloading ios player API JSON
[youtube] dQw4w9WgXcQ: Downloading android player API JSON
[youtube] dQw4w9WgXcQ: Downloading m3u8 information
[info] dQw4w9WgXcQ: Downloading 1 format(s): 251
[download] Destination: /data/data/com.termux/files/home/storage/movies/ytdl/20091025__Rick_Astley_-_Never_Gonna_Give_You_Up_Official_Music_Video.webm
[download] 100% of 3.28MiB in 00:00:00 at 6.91MiB/s
I have no idea what you’re on about. Literally every phone I have ever owned turns off mobile data when I’m connected to Wi-Fi, and turns it back on again when my Wi-Fi disconnects.