Seedance 2.5 from ByteDance and Kling 4.0 from Kuaishou are the two big Chinese AI video models of late 2026, and on paper they look alike: both make 30-second clips with sound in one pass, both follow reference images and videos, and both can edit existing footage. In practice they suit different jobs — and differ a lot in price.
This guide compares them head to head. All specs and prices are what you get on SeeVid, where both run with one credit balance, so you can test the same prompt on each.
The Short Answer
- Pick Seedance 2.5 when you need the most control: many characters or products in one shot, long scripted prompts, extending a clip, or cheap drafts before the final render.
- Pick Kling 4.0 for long clips with stereo sound at a lower price — about 35–45% cheaper per second than Seedance 2.5.
Side-by-Side Comparison
| Seedance 2.5 | Kling 4.0 | |
|---|---|---|
| Maker | ByteDance | Kuaishou |
| Clip length | 4–30 s, or Auto | 3–30 s |
| Resolution on SeeVid | 480p, 720p, 1080p | 720p, 1080p |
| Sound | Generated with the video | Two-channel stereo with lip sync |
| Image-to-video | First + last frame | First + last frame |
| Reference images | Up to 30 | Up to 10 |
| Reference videos | Up to 10 (30 s total) | Up to 5 (30 s total) |
| Reference audio | Up to 10 | — |
| Video editing | Yes | Yes |
| Video extending | Yes (forward or backward) | — |
| Draft mode | Yes (480p draft, upgrade the keeper) | — |
| Max prompt length | 10,000 characters | 2,500 characters |
| Price per second | Higher | About 35–45% lower |
1. Clip Length
Both models generate up to 30 seconds in one pass, which keeps a character, product and lighting consistent across a whole ad or story beat. Seedance 2.5 adds an Auto length, where the model picks a duration that suits the prompt, and an extender that continues a clip forward or backward if 30 seconds is not enough.
Winner: tie on length; Seedance 2.5 if you need to go longer.
2. Picture and Motion
Both produce cinematic 1080p footage with stable motion and camera work. Kling 4.0 was built for steadier action — tracking shots, orbits, fights, dance and vehicles — and renders text and logos more accurately than Kling 3.0. Seedance 2.5 is strongest when a shot must match references closely: faces, outfits, products and locations taken from your uploads.
Seedance 2.5 also offers 480p, a cheap way to test ideas. Kling 4.0 starts at 720p.
Winner: close; run the same prompt on both for your style of shot.
3. Sound
Both generate audio with the picture — music, effects and dialogue with lip sync. Kling 4.0 outputs two-channel stereo and supports lip sync in more languages than before (adding Portuguese, German, French, Hindi and more). Seedance 2.5 can follow up to 10 reference audio clips, so you can give it the music or voice you want instead of describing it.
Winner: Kling 4.0 for stereo dialogue; Seedance 2.5 when you want to supply your own audio.
4. References and Consistency
This is the biggest difference.
- Seedance 2.5 takes up to 30 images, 10 videos and 10 audio clips, tagged in the prompt as
@image1,@video1,@audio1. It is built for shots with several characters, products, outfits and locations at once. - Kling 4.0 takes up to 10 images and 5 videos — enough for a couple of characters and a style.
Winner: Seedance 2.5, clearly, for brand and multi-character work.
5. Editing and Extending
- Both edit video. Seedance 2.5's AI Video Editor and Kling 4.0's video edit can swap backgrounds, products, outfits or styles in a 3–30 second clip while keeping the motion.
- Only Seedance 2.5 extends. The AI Video Extender adds seconds before or after a clip.
Winner: Seedance 2.5.
6. Prompts
Seedance 2.5 accepts prompts of up to 10,000 characters — enough to script a 30-second sequence shot by shot. Kling 4.0 accepts 2,500 characters, so long clips need tighter prompts. Need ideas? See our 50 Seedance prompts.
Winner: Seedance 2.5.
7. Price
Credits per clip on SeeVid, with sound included:
| Length | Seedance 2.5 720p | Kling 4.0 720p | Seedance 2.5 1080p | Kling 4.0 1080p |
|---|---|---|---|---|
| 5 s | 90 | 59 | 163 | 88 |
| 10 s | 181 | 117 | 325 | 176 |
| 15 s | 271 | 176 | 488 | 264 |
| 30 s | 542 | 352 | 976 | 528 |
Prices as of November 2026. The generator always shows the current price before you generate.
Kling 4.0 is about 35% cheaper at 720p and 45% cheaper at 1080p. Seedance 2.5 narrows the gap with draft mode: drafts cost the 480p price, and you upgrade only the take you keep. See the Seedance 2.5 pricing guide and what Kling 4.0 costs.
Winner: Kling 4.0 on price per second.
Which One for Which Job?
| Job | Pick | Why |
|---|---|---|
| Ad with several products and a recurring character | Seedance 2.5 | Up to 30 reference images |
| Long clip with dialogue on a budget | Kling 4.0 | Stereo sound, lower price |
| Fast action, sports, dance | Kling 4.0 | Steadier motion, lower price for testing |
| Make an existing clip longer | Seedance 2.5 | The only one that extends |
| Swap a product or background in a clip | Either | Both edit video |
| Shot-by-shot scripted sequence | Seedance 2.5 | 10,000-character prompts |
| Many cheap test takes | Seedance 2.5 drafts or Kling 4.0 | Drafts at 480p price, or Kling's lower rate |
A Practical Workflow
- Test the idea with Seedance 2.5 drafts or a short Kling 4.0 clip.
- Produce the final shot with the model that fits it: Seedance 2.5 for reference-heavy work, Kling 4.0 for long dialogue and action at a lower cost.
- Fix or extend with Seedance 2.5's editor and extender instead of starting over.
FAQ
Is Seedance 2.5 better than Kling 4.0? It gives more control — more references, longer prompts, extending and draft mode. Kling 4.0 is cheaper per second and has stereo sound. Both make 30-second clips and edit video.
Which is cheaper? Kling 4.0, by about 35% at 720p and 45% at 1080p. With draft mode, Seedance 2.5's test takes cost the 480p price.
Which is better for consistent characters? Seedance 2.5, thanks to up to 30 reference images and 10 reference videos.
What about Seedance 2.0? Seedance 2.0 is cheaper than both for clips up to 15 seconds and offers 4K. See Seedance 2.5 vs 2.0.
Can I use both with one account? Yes. On SeeVid both share one credit balance; choose the model per generation in the AI Video Generator.
Conclusion
Choose Seedance 2.5 when a shot needs many references, a long script, or extending; choose Kling 4.0 for long clips with stereo sound at a lower price. The quickest way to decide is to run the same prompt on both — on SeeVid they sit side by side.