A 90-second 21:9 trailer: three 30 s Seedance 2.5 jobs, $52.46

A 90 second 21:9 trailer on Sume is three 30 second Seedance 2.5 jobs joined on Timeline: $17.42 each at 720p, $52.26 in all, plus $0.20 for a Timeline render of up to two minutes. The total is $52.46. A 480p proof pass of the same three clips is $24.18, so a proof and a final together are about $76.

Kling 4.0 is listed with a 30 second maximum for the full model, per the fal explainer (read 2026-10-05), so even there a 90 second trailer is several clips. On Sume today, Seedance 2.5 is the model that takes both 21:9 and 30 seconds.

The clips and the join

The video docs give seedance-2.5 a range of 4 to 30 seconds, and the catalog lists 21:9 in its ratios. At 720p, 21:9 is 1470 x 630 pixels, and a 30 second clip is $17.42. At 1080p it is 2205 x 945 and $42.85, and at 480p it is 992 x 432 and $8.06.

The Timeline join is $0.10 per output minute, rounded up, so 90 seconds is two billable minutes. The Timeline docs allow up to 1,800 seconds of audio and 200 video slots, and a render with more than 12 slots is chunked by default.

A 90 second 21:9 trailer, three routes

Which route

The last row shows the other way to get there. H3 Max takes 21:9 at 5 to 15 seconds with native stereo audio, and a 15 second 1080p clip is $3.00, so six of them are $18.00. You then have six clips to match, not three, and each is a separate look. Use Seedance 2.5 when you want a long, calm take and H3 Max when you want cheap, quick shots with sound.

Plan the proof pass first. At 480p the three 30 second clips are $24.18, and you can check framing and motion on a 992 x 432 frame before you spend $52.26. If one clip fails, you rerun $17.42 or $8.06, not the whole trailer.

Whichever you pick, keep the same prompt wording across the clips and say what must stay the same: the lead character, the colour of the light and the camera height. A trailer is judged on whether it reads as one piece, and the three 30 second takes are three separate samples from the model.

Budget and queue

Capacity matters for three parallel jobs. The admission docs list accepted job capacity by plan, from 6 on Free to 24 on Pro, so three jobs fit within the accepted capacity on any plan. Check the admission docs for how many run at once, because that decides how long the wave takes. Each job reserves its price at submit, so keep about $52.26 free for the three, and more if you submit a 480p proof first.

This script builds the three request bodies and the totals. It does not send them.

import json

CLIP = {"480p": 8.06, "720p": 17.42, "1080p": 42.85}
JOIN = 0.20

def jobs(resolution, n=3):
    return [{
        "model": "seedance-2.5",
        "prompt": f"Trailer shot {i + 1}: slow wide movement, cinematic light",
        "duration": 30,
        "resolution": resolution,
        "aspect_ratio": "21:9",
    } for i in range(n)]

for res, price in CLIP.items():
    print(res, "clips", round(3 * price, 2), "with join", round(3 * price + JOIN, 2))
print(json.dumps(jobs("480p")[0], indent=2))

Join

Before you start, decide where the cuts fall. Because each clip is an independent generation, the last frame of clip one does not match the first frame of clip two. Either pass the last frame of one clip as the first frame of the next, or cut on a change of scene so the join does not show. A one second dissolve between clips is within the Timeline limit, and costs nothing extra.

Join the finished clips on Timeline with a canvas that suits 21:9, for example 1470 x 630 for 720p clips, and set audio.duration_seconds to 90. If you want a soundtrack, attach it as the audio spine. Submit each clip with its own Idempotency-Key, and read the final amount from usage.cost. The jobs docs cover polling.