yt-dlp
yt-dlp is the main tool used in this guide. It supports YouTube and many other sites, chooses suitable video and audio streams, and asks ffmpeg to merge them when necessary.
Install and verify it first using Prerequisites.
One video
The smallest useful command is:
yt-dlp "https://www.youtube.com/watch?v=VIDEO_ID"
By default, current yt-dlp selects a good quality combination. Avoid copying format IDs such as 137+140 from another video: IDs and available codecs vary.
A preservation-oriented download
Create a directory for the archive, move into it, and run:
yt-dlp \
--write-info-json \
--write-description \
--write-thumbnail \
--write-subs \
--write-auto-subs \
--sub-langs "en.*,ja.*,id.*" \
--write-comments \
--mtime \
--download-archive downloaded.txt \
-o "%(uploader)s/%(upload_date)s - %(title)s [%(id)s].%(ext)s" \
"https://www.youtube.com/watch?v=VIDEO_ID"
This keeps the media plus an info JSON file, description, thumbnail, selected English/Japanese/Indonesian subtitles, comments, and a record that prevents accidental re-downloads. Adjust the language list for your collection. Comment extraction can be slow; omit --write-comments when speed matters. Not every site exposes every sidecar.
For an entire channel or playlist, use the same command with its playlist URL. First test with --playlist-end 1 so a filename or authentication mistake does not multiply across hundreds of videos.
Formats and containers
Inspect what a page offers with:
yt-dlp --list-formats "URL"
Letting yt-dlp choose is usually best. If you need a constraint, describe the result rather than pinning a transient ID. This example limits video to 1080p while retaining a fallback:
yt-dlp -f "bv*[height<=1080]+ba/b[height<=1080]" "URL"
Do not append .mp4 after %(ext)s; that produces misleading names such as video.webm.mp4. If you need an MP4 compatibility copy, preserve the original and use --remux-video mp4 or the ffmpeg remux example only when the codecs are compatible.
Subtitles and live chat
List subtitle tracks first:
yt-dlp --list-subs "URL"
Download selected subtitle languages:
yt-dlp --write-subs --write-auto-subs --sub-langs "en.*,ja.*,id.*" "URL"
On supported YouTube pages, live_chat appears as a subtitle track. Save it as a sidecar with:
yt-dlp --skip-download --write-subs --sub-langs live_chat "URL"
Chat availability and replay completeness are controlled by YouTube. Verify that the resulting file exists and is non-empty.
Content that requires your account
Use cookies only for content your logged-in account is permitted to view. --cookies-from-browser avoids browser extensions and loose cookie exports:
yt-dlp --cookies-from-browser firefox "URL"
Replace firefox with a supported browser name. Some browsers must be fully closed before their cookie database can be read. If you use a separate browser profile, append its name or path using the syntax documented by yt-dlp --help.
Cookies can grant access to your account. Never commit them to Git, paste them into an issue, share them with another person, or store them inside the archive. Prefer a dedicated browser profile, keep it protected, and sign out or revoke sessions if a cookie file leaks.
Reusable configuration
After one-off commands work, place stable options in a configuration file:
--write-info-json
--write-description
--write-thumbnail
--write-subs
--write-auto-subs
--sub-langs en.*,ja.*,id.*
--mtime
--download-archive downloaded.txt
-o %(uploader)s/%(upload_date)s - %(title)s [%(id)s].%(ext)s
Keep account cookies and output paths out of a configuration you intend to share. Use --ignore-config when testing whether a saved option causes a problem.
Updating and diagnostics
Start any diagnosis with:
yt-dlp --version
yt-dlp -U
yt-dlp --verbose "URL"
Use your package manager instead of -U when it installed yt-dlp. Before sharing a verbose log, remove usernames, local paths, cookies, query tokens, and private URLs. See Troubleshooting for common failures.