Facebook Reels API video length: 3 to 90 seconds, 24 to 60 fps

To publish a Reel on a Facebook Page through the Video API, the video must run 3 to 90 seconds, be 9x16, and run at 24 to 60 frames per second. Meta recommends 1080x1920 and lists 540x960 as the minimum.

Sume can reach that length range by joining clips in Timeline 1.0 at 24, 25, 30 or 60 fps; codec details are outside what Sume exposes. Values are from Meta's page as read on 2026-09-29.

What does the Reels publishing guide require?

The page recommends .mp4 and accepts H.264 or H.265 (VP9 and AV1 also listed), 4:2:0 chroma, a closed GOP of 2 to 5 seconds, and stereo AAC-LC audio at 128 kbps or higher, 48 kHz.

Which Sume tools reach 90 seconds?

A single generation is short: seedance-2.5 lists 4 to 30 seconds and wan-3.0 lists 2 to 30. Most other models cap at 15 or less. For a 90-second Reel, build it from several clips: Timeline 1.0 takes an audio spine of 1 to 1800 seconds and 1 to 200 video[] slots.

Set output.width 1080, height 1920 and fps 30 (or 24, 25, 60) to stay in Meta's range.

curl -X POST https://api.sume.com/v1/timeline-1.0/render \
  -H "Authorization: Bearer $SUME_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: fb-reel-90s-001" \
  -d '{
    "audio": {
      "url": "https://media.sume.com/artifacts/artf_demo/voice.wav",
      "duration_seconds": 24
    },
    "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 }
    ],
    "output": { "width": 1080, "height": 1920, "fps": 30 }
  }'

What about the closed GOP and AAC rules?

Sume's docs do not list GOP length, chroma format or audio sample-rate controls, and callers cannot set codec, bitrate or CRF on Timeline. Render, then probe the result with POST /v1/video-inspect and compare with the table before you publish.

What are the limits of this answer?

This post covers the Facebook Page Reels API page only. Instagram has its own limits (3 s to 15 min); see the linked Instagram post.