Longest single shot per request: Vidu, Veo, Grok, Wan, Seedance

The longest single shot per request is 30 seconds, on Wan 3.0 (Alibaba and Sume) and Seedance 2.5 (Sume). Vidu Q4 stops at 16, Grok Imagine at 15, HappyHorse 1.0 at 15, Gemini Omni Flash 1.1 at 10 and Veo 3.1 at 8.

The table gives each vendor's limit as read on 2026-10-10 and the Sume row that matches, if any.

The limits side by side

Vendor limits come from the pages listed in the sources. Sume limits come from the Video Generation docs and the capability table in the API code. Where a vendor lists a range, the table shows the maximum.

Why 30 seconds is not always the answer

A long single shot is useful when you want continuity, such as a walk-through or a slow reveal. But it is also the most expensive way to fail. A 30-second Seedance 2.5 clip at 720p bills $17.334 on Sume, and a 30-second Wan 3.0 clip at 720p bills $3.75. If the first five seconds are wrong, you have paid for all 30.

Test with a short clip on the same row, then scale the duration. The Sume rates are linear in seconds for Wan, so the test costs a fixed fraction of the final shot.

The Omni exception

Sume's docs line that each other catalog model tops out at 15 seconds is not true for Gemini Omni Flash 1.1, which accepts 3 to 10 seconds. If you plan a 12-second shot, Omni will refuse it. Pick Seedance 2.5, Wan 3.0, MiniMax H3 (5 to 15 seconds) or the Grok row (up to 15 seconds).

Read supported_durations in GET /v1/videos/models at run time instead of hard-coding the number, since catalogs change.

Choosing for a duration

Under 10 seconds with 4K or a reference clip: Omni. Up to 15 seconds from a still: Grok on Sume is the cheapest. Over 15 seconds: only Wan 3.0 and Seedance 2.5 qualify on Sume, and Wan is much cheaper per second at every resolution. Vidu Q4's 16 seconds would give one more second than Grok, but Vidu is not on Sume. The Video Generation page lists every limit.

Splitting a long shot instead

If a 30-second shot is too costly to risk, you can split it into two 15-second requests on a row that supports it and join them in an editor. Each half costs half as much on a per-second basis, and you can reject a bad half without paying for the other. The cut will show unless you plan it, so choose a moment such as a camera whip or an object passing the lens.

On Sume, Wan 3.0 is the practical choice for this approach at $0.125 per second at 720p, so two 15-second halves bill $1.875 each.