You can also use special names to select particular edge case formats:
- `best`: Select the best quality format represented by a single file with video and audio. - `worst`: Select the worst quality format represented by a single file with video and audio. - `bestvideo`: Select the best quality video-only format (e.g. DASH video). May not be available. - `worstvideo`: Select the worst quality video-only format. May not be available. - `bestaudio`: Select the best quality audio only-format. May not be available. - `worstaudio`: Select the worst quality audio only-format. May not be available.
- `filesize`: The number of bytes, if known in advance - `width`: Width of the video, if known - `height`: Height of the video, if known - `tbr`: Average bitrate of audio and video in KBit/s - `abr`: Average audio bitrate in KBit/s - `vbr`: Average video bitrate in KBit/s - `asr`: Audio sampling rate in Hertz - `fps`: Frame rate
- `ext`: File extension - `acodec`: Name of the audio codec in use - `vcodec`: Name of the video codec in use - `container`: Name of the container format - `protocol`: The protocol that will be used for the actual download, lower-case (`http`, `https`, `rtsp`, `rtmp`, `rtmpe`, `mms`, `f4m`, `ism`, `http_dash_segments`, `m3u8`, or `m3u8_native`) - `format_id`: A short description of the format - `language`: Language code
# Download best mp4 format available or any other best if no mp4 available $ youtube-dl -f 'bestvideo[ext=mp4]+bestaudio[ext=m4a]/best[ext=mp4]/best'
# Download best format available but no better than 480p $ youtube-dl -f 'bestvideo[height<=480]+bestaudio/best[height<=480]'
# Download best video only format but no bigger than 50 MB $ youtube-dl -f 'best[filesize<50M]'
# Download best format available via direct link over HTTP/HTTPS protocol $ youtube-dl -f '(bestvideo+bestaudio/best)[protocol^=http]'
# Download the best video format and the best audio format without merging them $ youtube-dl -f 'bestvideo,bestaudio' -o '%(title)s.f%(format_id)s.%(ext)s'
