Kling 4.0 Flash makes 20-second clips: which Sume model reaches 20 s?

Kling 4.0 Flash is reported to make 3 to 20 second clips at 720p, and only for Ultra Yearly subscribers so far. On Sume, kling-3 tops out at 15 seconds, so a 20 second single clip means seedance-2.5 (4 to 30 seconds) or wan-3.0 (2 to 30 seconds), neither of which is a Kling model.

What is actually live from Kling?

Kling's homepage presents Kling 4.0 with a Try Now button but, in the text I could read, gives no durations or dates (read 2026-10-02). The Flash specs below come from Tech Times' 30 September report, a press source rather than Kling's own spec page, so treat them as reported figures.

The same report says the full Kling 4.0, with up to 30 seconds and 4K, is still due in October, and that 4K 10-bit HDR output was listed as coming soon.

Which Sume models reach 20 seconds?

Sume's video router docs list each model's duration envelope. Only the rows below cover 20 seconds in one generation; everything else is capped at 15 seconds.

What if you want Kling's look?

Sume lists no Kling 4.0 or Kling 4.0 Flash id, and kling-3 is capped at 15 seconds with no reference inputs. To get 20 seconds from Kling-style output you would chain clips: end one at a frame and start the next from it. Sume documents first and last frame input for kling-3, but a chain shows seams in motion and audio, and each clip is billed on its own.

Direct access to Flash through Kling's own app is the only route today, and Kling had no API price for it when the report was written. Do not plan a budget around a Flash API until Kling publishes one.

A quick decision

• Need exactly 20 seconds in one take on Sume: seedance-2.5 or wan-3.0.
• Need Kling 3.0 behavior: kling-3 at up to 15 seconds.
• Need Kling 4.0 Flash specifically: use Kling's app if you hold an Ultra Yearly plan.
• Need 30 seconds and 4K from Kling: wait for the October release and read its API page.