instagram.media.video_size_max - letmepost.dev

What it checks

byteLength <= 1_000_000_000 per video item. Reels also have a 90-second duration cap that’s enforced at platform level (preflight doesn’t probe duration without ffprobe).

Why

Meta’s Instagram Reels documentation caps individual videos at 1 GB. Beyond that the upload is rejected.

Failure response

{
  "error": {
    "code": "preflight_failed",
    "rule": "instagram.media.video_size_max",
    "platform": "instagram",
    "message": "Video is 1450000000 bytes; Instagram allows at most 1000000000.",
    "remediation": "Compress the video under 1000000000 bytes (Instagram Reels accepts up to 1 GB)."
  }
}

Remediation

Re-encode at a lower bitrate. For a 60 s Reel at 1080×1920, ~6 Mbps is plenty:

ffmpeg -i input.mp4 -c:v libx264 -b:v 6M -c:a aac -b:a 128k -movflags +faststart output.mp4

instagram.media.mime_allowed