TikTok ad at 9:40 and 516 kbps: 37.4 MB and a $1.00 Sume render

A 9 minute 40 second TikTok ad (580 seconds) encoded at the 516 kbps minimum is about 37.4 MB, so the 500 MB file cap never matters; the 10-minute length limit and the bitrate floor do. On Sume, a Timeline 1.0 render of 580 seconds bills 10 minutes at $0.10 per minute, which is $1.00.

The TikTok limits

TikTok's help page for non-Spark video ads lists vertical 9:16 at 540 by 960 pixels or more, horizontal 16:9 at 960 by 540 or more, square 1:1 at 640 by 640 or more, formats .mp4, .mov, .mpeg, .3gp and .avi, a duration of up to 10 minutes, a file size of 500 MB or less, and a bitrate of 516 kbps or more (read 2026-10-09).

Which limit binds first? At the lowest allowed bitrate, size grows with length. Compute it: 580 seconds times 516 kilobits is 299,280 kilobits, divided by 8 is 37,410 kilobytes, about 37.4 MB. Reaching 500 MB at 516 kbps would take roughly 7,752 seconds, so the 600-second cap ends the ad long before the size cap does. A higher bitrate changes this: 500 MB over 580 seconds allows about 6.9 Mbps.

Rendering a 580-second ad

Timeline 1.0 takes one audio spine up to 1,800 seconds and 1 to 200 video slots, and returns one MP4. The default output is 1080 by 1920, which clears the 540 by 960 vertical minimum. The spine length sets the output length, so set audio.duration_seconds to 580. The reserve is the ceiling of seconds over 60, which is 10 minutes, so the render costs $1.00.

POST /v1/timeline-1.0/plan is the free preflight. It returns duration_seconds, billable_minutes and estimated_cost_usd_micros without creating a job, so run it first and confirm 10 billable minutes.

• Render: $0.10 per output minute, rounded up, so 580 s and 600 s both bill $1.00.
• Plan preflight: unbilled.
• Slots: up to 200, and the render runs chunked above 12 segments.

Check the finished file

The render does not expose bitrate controls, so probe the result with video inspect. Its probe is free and reports the clip properties. If the average bitrate lands under 516 kbps, a very static ad can encode low; check before uploading rather than after review rejects it. If the file passes, upload it as a non-Spark ad.

A practical note

A final caution about bitrate. The 516 kbps number is a floor, and platforms may re-encode your file, so do not target the floor. If the render comes back near 516 kbps, a fast-moving ad may look soft after TikTok processes it. Check the probe from video inspect, keep a copy of the exact file you upload, and compare the ad in the Ads Manager preview. If you must cut file size, shorten the ad rather than lowering quality, since the 10-minute cap is the limit that already binds.