Meta's 4 GB video cap at Sume's 30-minute render limit: 17.8 Mbps

The short answer

Meta lists a 4 GB maximum file size for Instagram Feed, Instagram Reels and Facebook Feed video ads, and the longest single file Sume's Timeline 1.0 will render is 1,800 seconds (30 minutes). If 4 GB means 4,000 MB, a 30-minute file fits as long as its average bitrate is under 17.78 Mbps (32,000 megabits divided by 1,800 seconds). Real ad files almost never get near that, so size is rarely the constraint; duration is.

Limits side by side

Meta's three ad-guide pages read 2026-10-09 give different length ranges for the same 4 GB cap. The last column divides 32,000 megabits by the longest length each placement allows, which shows how much bitrate headroom there is at the extreme. Meta's pages do not say whether GB is decimal or binary, so treat the figures as approximate.

What Sume can render in one file

Timeline 1.0 takes audio.duration_seconds from 1 to 1,800 and 1 to 200 video slots, and renders one MP4 at the public rate of $0.10 per output minute, rounded up (docs read 2026-10-09; the live rate is in the public catalog). The default output is 1080x1920. So a Reels-length ad (15 minutes) is one job, $1.50, while a 30-minute file is $3.00.

At the 1,800-second ceiling the bitrate headroom is 17.78 Mbps, which is far above what a 1080p or 1440p social ad needs. A Reels ad at its 15-minute maximum could average up to 35.56 Mbps before reaching 4 GB. The two placements where the arithmetic bites are the long ones: an Instagram Feed ad near 60 minutes would need to stay under 8.89 Mbps, and Sume cannot render that length as one Timeline job anyway.

What to check on the file you deliver

Sume compiles ffmpeg on the server and rejects client-supplied codec and crf fields, so you do not set a bitrate. Measure the delivered MP4 instead. Meta's pages also list container rules that are independent of size: for Reels, H.264, square pixels, fixed frame rate, progressive scan and stereo AAC at 128 kbps or higher, and Instagram Feed's page says videos should not contain edit lists or special boxes in the container.

• 15-minute Reels cut: one Timeline job, ceil(15) x $0.10 = $1.50.
• 30-minute cut, the Sume maximum: ceil(30) x $0.10 = $3.00, average bitrate under 17.78 Mbps to stay inside 4 GB.
• Anything past 1,800 seconds: the docs describe no single-render path, so plan the file outside Sume.