Kling 4.0 vs Seedance 2.5
Two 30-second models with native audio, both running in our generator. Here is where they actually differ.
This comparison sticks to six axes: length, reference inputs, resolution, price, audio and access. Vendor capability claims are quoted only from Kling's and ByteDance's own announcements and fal's published API schemas; on-site limits and credit prices come from what this site enforces and pays. Where something is unpublished or not yet exposed here, it is marked as such.
Both models are available on ImagineToVideo
Seedance 2.5 went live on ImagineToVideo on August 7, 2026 and Kling 4.0 on October 26, 2026, both through fal's public API. You can run the same prompt on each and compare. Same-prompt side-by-side renders for this page are being produced and will be added here; the specification rows below are verified today. Rows marked as vendor claims describe each model's full API, which can be wider than what this site exposes.
Both sides last verified on
Where the two actually differ
Both reach 30 seconds in one pass
fal's Kling 4.0 API accepts 3 to 30 seconds per generation, and Kling 4.0 can split that into shots with per-shot prompts. ByteDance describes Seedance 2.5 as producing 30 seconds of audio and video in a single pass. On this axis the two claim the same ceiling, and both offer 3–15, 20 or 30 seconds here.
Reference handling is the real gap today
On this site Seedance 2.5 takes up to nine reference images plus up to nine reference videos. Kling 4.0 here takes a start frame and an optional end frame; its API also documents up to 15 references (10 images, 5 videos, 7 subjects), which ImagineToVideo has not exposed yet.
Kling 4.0 is cheaper per clip and goes to 1080p
On fal, Kling 4.0 is $0.157 per second at 720p and $0.235 at 1080p against roughly $0.47 at 720p for Seedance 2.5. On this site a 5-second 720p clip is 35 credits on Kling 4.0 and 100 on Seedance 2.5; a 30-second clip is 215 credits at 720p or 320 at 1080p on Kling 4.0 against 650 at 720p on Seedance 2.5.
Audio: stereo versus quoted dialogue
Kling 4.0 generates dialogue, effects and ambience as two-channel stereo with lip sync, always on. Seedance 2.5 generates native audio and turns lines in double quotes into lip-synced speech. Neither lets you upload your own voice track here.
The six axes
Vendor capability rows quote Kling's launch material and ByteDance's release announcement. Resolution, price and credit rows come from what ImagineToVideo enforces and what fal publishes.
| Kling 4.0 | Seedance 2.5 | |
|---|---|---|
Maximum duration | 30 seconds of audio and video in a single pass, per ByteDance's release announcement. Vendor claim; not independently reproduced. | |
Reference material on ImagineToVideo | Up to nine reference images plus up to nine reference videos, with @Image and @Video references in the prompt. | |
Resolution on ImagineToVideo | 720p or 1080p; 16:9, 9:16, 1:1, 21:9 Kling announces 4K and 10-bit HDR; fal's API does not offer them yet. | 480p or 720p; 16:9, 9:16, 1:1, 4:3, 3:4, 21:9 |
Price per second on fal | ||
Credits on ImagineToVideo | 5 s: 35 at 720p, 50 at 1080p. 30 s: 215 at 720p, 320 at 1080p. | 5 s: 50 at 480p, 100 at 720p. 30 s: 315 at 480p, 650 at 720p. |
How you get access |
Six axes and no more: only points where both sides have something on the record. Prices are fal's published rates on 2026-10-26 and can change.
Which one to pick
You work from a reference library
Seedance 2.5. On this site it takes up to nine reference images plus up to nine reference videos and turns quoted lines into lip-synced speech. Kling 4.0 here takes a start and end frame only until its reference mode is exposed.
You want 1080p, stereo audio and a lower credit cost
Kling 4.0. It reaches 1080p where Seedance 2.5 stops at 720p, runs to the same 30 seconds, lets you split the clip into prompted shots, and costs about a third as much per clip at 720p.
How this comparison was put together
So you can reproduce it, or catch us if a source moves.
Take each side's own sources
Kling 4.0 from Kling's September 28 announcement, its October 15 launch release and fal's published API schema. Seedance 2.5 from ByteDance's release announcement and fal's model page. No summary or aggregator page is used on either side.
Keep the axes to what both have on the record
Duration, references, resolution, price, credits and access are the six points where both sides have published something or where this site enforces a limit. Anything else would be one side's marketing against the other's silence.
Mark the gaps instead of filling them
Where a capability exists in the API but not on this site yet, such as Kling 4.0's 15-reference mode, it carries a ⚠️ rather than being counted as available.
Add same-prompt renders, then re-check weekly
Side-by-side clips from the same prompt are being produced and will be embedded on this page. Every source above is checked again each week, and any change is written into our Kling 4.0 page's timeline the same day.
Kling 4.0 vs Seedance 2.5: common questions
Which is better, Kling 4.0 or Seedance 2.5?
Output-quality rankings would still be guesswork: no rigorous third-party benchmark covers both. On what is documented, Seedance 2.5 offers far more reference control on this site today, while Kling 4.0 reaches 1080p, generates stereo audio and costs less per second. Both run on ImagineToVideo, so the fastest way to decide is the same prompt on each.
Can I use either of them today?
Yes, both. Seedance 2.5 has been on ImagineToVideo since August 7, 2026 and Kling 4.0 since October 26, 2026. Pick either from the model list in the generator.
Which one generates longer video?
They reach the same ceiling. fal's Kling 4.0 API accepts 3 to 30 seconds and Seedance 2.5 produces up to 30 seconds in one pass; this site offers 3 to 15, 20 or 30 seconds on both. The difference between them is not length.
What do they cost?
On fal, Kling 4.0 costs $0.157 per second at 720p and $0.235 at 1080p, audio included. Seedance 2.5 is token-billed, roughly $0.22 per second at 480p and $0.47 at 720p with audio. On ImagineToVideo a 5-second 720p clip is 35 credits on Kling 4.0 and 100 on Seedance 2.5, and a 30-second 720p clip is 215 against 650.
Both are live. Pick by the job.
Run the same prompt on Kling 4.0 and Seedance 2.5 and compare. Start with the $0.99 Starter Pack, no subscription needed.