TikTok Spark Ads have no length cap; non-Spark stops at 10 min

TikTok's Auction In-Feed Ads page lists Spark Ads with no duration restriction, and non-Spark ads as up to 10 minutes. So only a non-Spark upload needs a trim when your clip is longer than 600 seconds; with Sume that is one video trim of up to 900 seconds output for $0.02.

That 900-second output cap is itself longer than TikTok's 600 seconds, so a trim that fits TikTok has to be set shorter than Sume's own limit. The figures here come from TikTok's page (read 2026-10-10) and the Sume docs.

The two columns on TikTok's page

Spark Ads boost an existing organic post, and the page lists them with formats mp4 or mov, no duration restriction, and a caption display of a maximum of 4 lines including emojis. Non-Spark ads are uploaded as ad creative and carry the fuller list: 9:16 recommended at 540 x 960 or more, up to 10 minutes, 500 MB or less and 516 kbps or more.

The page does not give a Spark Ads file size or resolution in the figures I fetched, so I am not quoting any. A Spark Ad also starts from a post that already exists, so the clip's length was set when you published it.

Which path needs a trim

The decision is about where the video already lives. If the clip is a published organic post you want to boost, the page lists no duration restriction for Spark Ads, and there is nothing to trim on TikTok's account. If you are uploading new creative as a non-Spark ad, the 10-minute limit applies, and a longer file needs a cut.

Trimming for the non-Spark path

Video trim needs a start and exactly one of end or duration. Send duration 600 for a clean ten-minute cut, or a smaller value to leave headroom. The source can be up to 1800 seconds and the output up to 900 seconds, so a 25-minute recording is a valid source. If end falls beyond the source, Sume clamps it and warns with trim_clamped_to_source.

Exact precision is the default and re-encodes frame-accurately. Keyframe precision is a stream copy and can start a GOP early, so re-base your times against actual_start_seconds. For an ad, exact is the safer choice because the first frame is your hook.

• Import the clip first; trim only reads media.sume.com files.
• Send an Idempotency-Key header.
• Read duration_seconds in the result before you upload.

What this does not settle

Spark Ads have their own rules around authorization and the source post, and those are on TikTok's side. Whether a very long Spark Ad performs is a different question from whether it is allowed. For AI-generated video, also read TikTok's disclosure policy before boosting; that is covered in the neighbouring posts, and it applies whichever path you choose.

It is also worth separating two questions that the page keeps apart. One is whether a duration is allowed, which is what the table answers. The other is whether the video is any good at that length, which no spec page can tell you. A 10-minute non-Spark ad is legal, and so is a 3-minute one, and a short hook-first cut is usually easier to review and to re-render if you need to change a line.

For AI-generated clips specifically, long cuts multiply the surface where a disclosure must stay visible. If the AI label or your own caption is burned into the file, a trimmed 60-second version and a 10-minute version both need it. Trim first, add the disclosure second, and measure the final file once.