TikTok's 540x960 minimum: Vidu Q4 540P or a Sume 720p clip?

The short answer

TikTok's non-Spark video ad specifications set a minimum of 540 x 960 pixels for 9:16. A 720p vertical clip from Sume is 720 pixels on its short side, which clears it, and costs $0.125 per second on Gemini Omni Flash 1.1. The cheapest Omni tier, 360p at $0.0375 per second, does not clear it. Vidu Q4 Preview is sold at a 540P tier from $0.045 per second, but its release does not give pixel dimensions or aspect ratios, so whether its 540P output meets the 540 x 960 minimum is a question for the vendor.

TikTok's non-Spark ad limits

These are the platform limits that matter when you pick a generation tier.

What each tier costs per 10 seconds

Omni accepts 16:9 or 9:16 and 3 to 10 seconds, so a 10-second vertical clip is its maximum. At 720p that is 10 x $0.125 = $1.25. At 1080p it is 10 x $0.1875 = $1.875. At 360p it is 10 x $0.0375 = $0.375, but the frame is 360 pixels wide, below the 540 minimum, so it cannot go into the ad slot as is. Vidu's 540P list rate for 10 seconds is 10 x $0.045 = $0.45.

Wan 3.0 at 720p is also $0.125 per second, with a 2 to 30 second range. Check that its supported_aspect_ratios lists 9:16 before you plan on it.

Check the output, not the label

Resolution names are not pixel counts. After the first clip, read the actual width and height with Sume's video inspect route, described in the video inspect docs, and compare it with the table above. Also check the file's bitrate, since the 516 kbps floor applies to the uploaded file, and a heavily compressed export can fall under it. Sume's video generation docs list each row's accepted aspect ratios.

Scaling to a campaign

For 20 vertical ads of 10 seconds each, Omni at 720p costs 20 x $1.25 = $25.00 and Omni at 1080p costs 20 x $1.875 = $37.50. Allow for retakes by multiplying by the number you expect, as the three-take example in this series does. The extra 50% for 1080p buys headroom against compression on upload, but the platform spec only asks for 540 x 960, so 720p is enough to pass. If you later find that a 720p export looks soft after TikTok re-encodes it, move up one tier for the final render only.