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SPECS ONLY · NOT TESTEDKling 4.0 vs Veo 3.1 vs Seedance 2.5: Specs Compared
Updated · From each company's own documentation
On paper, Kling 4.0 is the only one of the three that combines 30-second clips with up to 4K and 10 keyframes. But it is not out yet. Veo 3.1 and Seedance 2.5 are available today. Seedance 2.5 accepts far more references, and Veo 3.1 has the longest extension. We compare published specs only; we have not tested Kling 4.0.
- Longest single clip
- Kling 4.0 and Seedance 2.5 Both up to 30 seconds
- Highest resolution
- Kling 4.0 and Veo 3.1 Both list 4K (Veo: 8-second clips only)
- Most references
- Seedance 2.5 Up to 50, vs 15 for Kling 4.0
- Most keyframe control
- Kling 4.0 First & last frames plus up to 10 keyframes
- Longest with extension
- Veo 3.1 Up to 148 seconds, at 720p
- Available today
- Veo 3.1, Seedance 2.5 Kling 4.0: Flash only, full model in October
Kling 4.0 vs Veo 3.1 vs Seedance 2.5: spec table
Each column uses only that company's own pages. "Not listed" means the official source we used does not state it. Kling 4.0 figures are announced, not yet released.
| Kling 4.0 | Veo 3.1 | Seedance 2.5 | |
|---|---|---|---|
| Maker | Kling AI (Kuaishou) | ByteDance | |
| Status | Announced; full release planned for October 2026. Kling 4.0 Flash in limited early access | Available (Gemini API) | Released July 31, 2026; API on BytePlus |
| Clip length per generation | 3–30 seconds (Flash: 3–20) | 4, 6 or 8 seconds (8 only at 1080p and 4K) | 4–30 seconds |
| Extension | Up to 2 minutes total (coming soon) | +7 seconds per extension, up to 148 seconds, 720p only | Multiple rounds of extension |
| Resolution | 720p / 1080p / 4K (Flash: 720p) | 720p / 1080p / 4K | 480p / 720p (BytePlus API) |
| HDR | 10-bit HDR at 1080p and 4K (coming soon) | Not listed | Not listed |
| Aspect ratios | 21:9, 16:9, 1:1, 9:16, Auto | 16:9, 9:16 | Not listed |
| Audio | Two-channel stereo, lip sync | Native audio | Audio and video generated together |
| References | Up to 15 (10 images, 5 videos, 7 subjects; voice included) | Up to 3 reference images | Up to 50 (30 images, 10 videos, 10 audio clips) |
| Frame control | First & last frames + up to 10 keyframes | First & last frames | Not listed |
| Video editing | Up to 5 input clips, 30 seconds combined | Not listed | Timestamp-level editing |
| Named speech languages | 9 "and more" | Not listed | Not listed |
| Where to use it | kling.ai (Flash: Ultra yearly plan) | Gemini API | Jimeng, Doubao; BytePlus ModelArk API |
What the specs say
Kling 4.0 vs Veo 3.1
Both list 4K. The difference is length: Veo 3.1 makes 4–8 second clips and reaches longer videos by extending at 720p, up to 148 seconds. Kling 4.0 promises up to 30 seconds in one generation at up to 4K, plus 10-bit HDR later. Kling 4.0 also takes more references (15 vs 3) and adds up to 10 keyframes on top of first and last frames. Veo 3.1 is usable today; full Kling 4.0 is not.
Kling 4.0 vs Seedance 2.5
Both promise 30-second clips in one pass. Seedance 2.5 is already released and accepts up to 50 references, including audio clips, against Kling 4.0's 15. Kling 4.0 lists higher resolution (up to 4K vs 720p on BytePlus's API) and keyframe control that Seedance's published material does not mention.
Kling 4.0 Flash vs the others
The part of Kling 4.0 you can use now, Flash, is 720p and up to 20 seconds, with no keyframes. That puts it closer to Seedance 2.5's API output than to Veo 3.1's 4K. See Kling 4.0 Flash for its full specs.
Specs are not quality. Motion, realism and prompt-following can only be judged by testing the models side by side, which we have not done for Kling 4.0. For Kling 4.0 against its predecessor, see Kling 4.0 vs Kling 3.0.
Comparison FAQ
Is Kling 4.0 better than Veo 3.1?
On published specs, Kling 4.0 offers longer single clips (30 vs 8 seconds), more references and more keyframes, while both list 4K. Veo 3.1 is available now and Kling 4.0 is not fully released, so no one can compare output quality fairly yet.
Is Kling 4.0 better than Seedance 2.5?
They match on 30-second clips. Kling 4.0 lists higher resolution and keyframe control; Seedance 2.5 takes far more references and is already released. Which is better will depend on testing once Kling 4.0 launches.
Which AI video model makes the longest clips?
In one generation, Kling 4.0 (announced) and Seedance 2.5 both reach 30 seconds. With extension, Veo 3.1 goes up to 148 seconds at 720p, and Kling says Kling 4.0 extension will reach 2 minutes (coming soon).
Why is Sora 2 not in this comparison?
OpenAI removed the Sora 2 models and its Videos API from the API on September 24, 2026, according to OpenAI's deprecations page ↗.
When will this page be updated?
When Kling 4.0 is fully released, and whenever Google or ByteDance change their published specs. We log Kling changes on the Kling 4.0 status page.