How many audio tracks can one Instagram Reel hold? Up to 20

One Instagram Reel can carry up to 20 audio tracks. Meta's Reels page for creators says: "Add up to 20 tracks to a single reel and visually align audio with elements like text, stickers, and clips while you're editing in the app." That is a limit for the in-app editor. If you build the sound outside the app, you do not have to stack 20 tracks on a phone timeline: you can decide the sound plan first and render it as one file.

What counts as a track?

The Meta page does not define the word beyond music and original audio, so I will not guess. Meta's Reels page lists the sources a Reel can use: the Instagram music library, original audio you record, and voiceover on clips. In practice each of those is one piece of audio on the timeline. Plan around the number 20 as a ceiling, and keep the plan small anyway: Meta's music guidelines say that "the greater the number of full-length recorded tracks in a video, the more likely it may be limited", and that shorter clips of music are recommended.

How does Sume handle several audio pieces?

Sume has no phone-style multi-track editor. It has three pieces that together cover most Reel sound plans, and each has its own limit in the docs.

Can I generate one of the tracks?

Yes, for the music bed. The Music Router takes a prompt; it rejects duration and duration_seconds, so you steer length in the prompt (for example "A 30-second track"). Because the length is a request and not a setting, trim the result to what you need by declaring audio.duration_seconds on the render, or fade it out with soundtrack.fade_out_seconds.

What does a render with several audio parts look like?

Declare the spine as slices and the clips on top. A plan call is unbilled and returns the duration, segment count and estimated cost before you commit to a render. Parts must sum to at least duration_seconds, and video[0].start must be 0.

curl -X POST https://api.sume.com/v1/timeline-1.0/plan \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "audio": {
      "duration_seconds": 24,
      "parts": [
        { "url": "https://media.sume.com/artifacts/artf_demo/voice-a.wav", "duration": 12 },
        { "url": "https://media.sume.com/artifacts/artf_demo/voice-b.wav", "duration": 12 }
      ]
    },
    "video": [
      { "source_url": "https://media.sume.com/artifacts/artf_demo/a.mp4", "start": 0, "duration": 12 },
      { "source_url": "https://media.sume.com/artifacts/artf_demo/b.mp4", "start": 12, "duration": 12 }
    ],
    "soundtrack": { "url": "https://media.sume.com/artifacts/artf_demo/bed.wav", "duck_db": 12, "fade_out_seconds": 2 }
  }'

How should I choose how many tracks to use?

Start from the viewer, not the limit. A speech-led Reel usually needs one voice and one low bed. A montage may use a few short music clips. Use the Timeline render for the final mix, then check the length against what you declared. If the plan needs more than 20 pieces, join some with Timeline audio first, since it returns one durable file with the concat offsets, and use that file as audio.url.