TikTok horizontal ad minimum is 960x540: which 16:9 sizes clear it

TikTok's in-feed specification page lists 16:9 horizontal video with a minimum of 960 x 540 pixels. A Sume Timeline 1.0 render at 960x540, 1280x720 or 1920x1080 clears it, since each edge is even and between 256 and 2160, and the render costs $0.10 per output minute, rounded up, at any of those sizes.

Which sizes clear it

Why 480p is not enough

Models can generate at 480p, as the video generation docs show for Seedance 2.5, and a 16:9 frame that is 480 tall is about 854 wide. That is below 960 x 540, so a 480p draft is a preview, not an upload. Scaling it up in Timeline adds pixels, not detail, and the TikTok check is on the file's size.

Other limits on the same page

For non-Spark ads, TikTok lists MP4, MOV, MPEG, 3GP or AVI, up to 10 minutes, 500 MB or less and a bitrate of at least 516 kbps. Timeline fits the ten minutes with room, since it renders up to 30. The Sume docs do not state a bitrate or a file-size cap, so measure the download.

What Sume does not do

Sume does not upload to TikTok Ads Manager and does not check a file against TikTok's page. TikTok lists 9:16 as its recommended ratio, so a horizontal ad is a choice, not a default.

For most horizontal ads, 1280x720 is the sensible middle: it clears the minimum by a wide margin, keeps the file small, and avoids upscaling a 720p source. Use 1920x1080 only when the source is 1080p; rendering a 720p clip at that size adds pixels without detail and makes the file bigger for no gain.