12-minute demo to a TikTok ad: one 600-s trim $0.02 or 3 cuts $0.06

A 12-minute demo is 720 seconds, which is 120 seconds over TikTok's non-Spark limit of 10 minutes. You have two cheap fixes on Sume. One Video trim with start 0 and duration 600 gives a 10-minute file for $0.02. Three trims of 240 seconds each give three 4-minute ads for 3 x $0.02 = $0.06, and 3 x 240 = 720 covers the whole demo (as of 2026-10-08). The TikTok page says Spark Ads have no duration restriction, so a Spark route needs no cut at all.

What the TikTok page says

The page, last updated June 2026, lists for non-Spark ads: up to 10 minutes, 500 MB or less, 516 kbps or more, and the file types .mp4, .mov, .mpeg, .3gp and .avi. For Spark Ads, it says the video format is .mp4 or .mov and the duration has no restriction.

The trim body

Video trim accepts a duration from 0.2 to 900 seconds and a source of up to 1800 seconds, so a 720-second source and a 600-second output are inside the limits. Send video_url (already on media.sume.com), start, and exactly one of end or duration. Sending both gives video_trim_range_conflict. The default precision exact re-encodes with libx264 at yuv420p, and the default audio keep remuxes the audio as AAC.

For the three-part split, cut at a natural pause near each boundary. A clean way is to probe first with Video inspect and its sentence segmentation, then use those times for the three starts. Keep each part under the limit with some room: 240 seconds is far below 600.

The 500 MB cap at 600 seconds

File size is a separate limit from length. At 600 seconds, 500 MB means an average of 500 x 8 / 600 = 6.67 megabits per second at most. Sume does not take a bitrate field, so you cannot set the number yourself, and the API refuses codec, crf and similar keys. Measure the finished file. If it is above 500 MB, the three-part route gives you three files that are each far smaller.

The shorter option has a second advantage that is not about size. Three separate 4-minute ads can be tested against each other, whereas one 10-minute ad is one creative. That is a marketing choice, not a TikTok rule, so decide it on your own results.

Which route to pick

Choose the Spark route when you can: the TikTok page lists no duration limit for it, and the 720-second file goes up as is. Choose the single trim when the first 10 minutes carry the message, and the three-part split when the demo has three self-contained chapters. In every case the Sume cost is tiny against the media spend, so choose on the creative. Remember the Idempotency-Key on each trim job, with a distinct key per part, such as demo-part-1, demo-part-2 and demo-part-3.