YouTube audio bitrate: stereo 384 kbps, and what Sume audio-detach is

YouTube's recommended audio bitrates are 128 kbps for mono, 384 kbps for stereo and 512 kbps for 5.1, with a 48 kHz sample rate. Sume's audio-detach can write 48 kHz, but its mp3 is fixed at 128 kbps, which is below the stereo figure, so use wav when you need the full-quality extract.

YouTube numbers are from its recommended upload encoding settings page (undated; read 2026-10-01); Sume numbers from the Audio detach docs.

What does YouTube recommend per channel layout?

The page also lists the audio codec as AAC-LC, Opus or Eclipsa Audio, channels as stereo or stereo plus 5.1, and the container as MP4. For Eclipsa Audio it recommends 128 kbps per channel.

What does Sume audio-detach output?

POST /v1/audio-detach takes a Sume-hosted clip and writes a new audio artifact. format is wav (default, pcm_s16le sample-exact) or mp3 (128 kbps). sample_rate is 16000, 44100 or 48000, and omitting it inherits the source. channels is source (default) or mono. A source with no audio track fails with detach_source_has_no_audio.

Which setting matches the YouTube numbers?

For a 48 kHz stereo master, ask for format: "wav" and sample_rate: 48000 with channels left at source. The wav is uncompressed, so it carries no bitrate target to miss. The mp3 option at 128 kbps would sit below YouTube's stereo recommendation; it matches the mono figure only if you also set channels: "mono".

curl -X POST https://api.sume.com/v1/audio-detach \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: yt-audio-001" \
  -d '{
    "video_url": "https://media.sume.com/artifacts/artf_demo/talk.mp4",
    "format": "wav",
    "sample_rate": 48000
  }'

Does the extract replace the audio in my upload?

No. Audio detach gives you a separate file, and the YouTube page asks for an MP4 container with AAC-LC, Opus or Eclipsa audio. If the clip itself goes up, the trim docs say exact mode remuxes kept audio as AAC but do not state its bitrate. See also Sume sets no bitrate field for video.