youtube-dl

youtube-dl –write-auto-sub

It will default to English, but you can specify another language with the flag –sub-lang:

youtube-dl –sub-lang sv –write-auto-sub

You can list all available subtitles with:

youtube-dl –list-subs

It’s also possible to skip the video and only download the subtitle if you add the flag –skip-download:

youtube-dl –sub-lang sv –write-auto-sub –skip-download

Alternative

Try yt-dlp for some additional features and workarounds. It uses the same flags as youtube-dl.