Model comparisons
Kling 4.0: Filtered. Seedance 2.0 Fast: Uncensored. Kling 4.0 renders up to 30 seconds per request; Seedance 2.0 Fast stops at 15.
Kling 4.0 image-to-video animates your opening frame into a clip of 3 to 30 seconds at 720p or 1080p. Add a closing frame and up to 8 in-between keyframes to direct the path; every clip comes with a stereo soundtrack.
View model details →View sample outputs →Seedance 2.0 Fast image-to-video from ByteDance starts the clip on a still you supply and animates it, with sound in the same pass. Clips run 4 to 15 seconds at 480p or 720p, and an optional closing still makes the shot arrive on a set frame.
View model details →View sample outputs →Compare
Start with the input you have, the result you want and your budget. These are the differences that affect that choice.
Compare the published examples, then try the same input on both models with matching settings.
The Spicy Index and Freedom Score for both models, from the same daily calculation as the leaderboards.
| Measure | Kling 4.0 | Seedance 2.0 Fast |
|---|---|---|
| Spicy Index | 86.5 | 73.5 |
| Freedom Score | Not enough evidence yet | 72.2 |
| Evidence | Tested 2 of 6 probe types · 2 runs | Tested 4 of 6 probe types · 44 runs |
| Range if the rest pass | 0.0–60.0 | 72.2–92.2 |
| Price | $1.08 per 5-second clip | $0.484 per 5-second clip |
| Reviews | No review yet | Read the Seedance 2.0 Fast review |
Preliminary · freedom evidence pending
See both on the leaderboard →Current price
A start price answers a different question than the one you have. These are the tiers both models publish, matched setting for setting, in US dollars per billed unit with no conversion step in between.
These two bill on different tiers, so there is no row to line up. Each one's own published tiers are listed here instead.
Kling 4.0: 720p $0.216 / output seconds · 1080p $0.324 / output seconds
Seedance 2.0 Fast: no audio · 480p $0.045 / output seconds · with audio · 480p $0.045 / output seconds · no audio · 720p $0.097 / output seconds · with audio · 720p $0.097 / output seconds
Arithmetic on the published rates at each model's own default setting, not a quote. The console prices your actual settings before a request is accepted.
About this comparison
Every row here is read from the JSON Schema the endpoint validates against, so it matches what the API will really accept rather than a feature list written by hand.
Swipe horizontally to compare all fields.
| Controls and limits | Kling 4.0 | Seedance 2.0 Fast |
|---|---|---|
| Supported tasks | image-to-video | image-to-video |
| Clip length | 3–30 seconds | 4–15 seconds |
| Resolution tiers | 720p · 1080p | 480p · 720p |
| Aspect ratios | auto · 16:9 · 9:16 · 1:1 · 21:9 | 16:9 · 9:16 · 4:3 · 3:4 · 1:1 · 21:9 · adaptive |
| Reference material | Up to 8 files | Not offered |
| Audio output | Yes | Yes |
| High-resolution tier | Yes | No |
| Seed | No | Yes |
| Execution | Submit, then poll or take the callback | Submit, then poll or take the callback |
| Request timeout | 60 minutes | 120 minutes |
| Availability | Live | Live |
Do low-filter models allow every request?
Two separate facts sit behind these labels. The first is what we do, which is nothing: no platform content filter, and no maturity flag to set on a request. The second is what each model does on its own, and that is the only part that varies between these two.
Kling 4.0
This model refuses requests beyond its own limits outright. Measured, not assumed — models we have not measured carry no label at all.
Seedance 2.0 Fast
This model declares no content filter. SpicyAPI forwards the request without adding a platform content scan; legal and consent duties remain with the customer.
Usage note Use only material you are authorised to process. Check consent, privacy, likeness, brand, and music rights; do not use output to deceive or impersonate.
Use these content labels to shortlist models, then open each model page for available examples and content-test details.
The label never changes your obligations. Age, consent, real-person likeness and the law where you operate stay with you, and SpicyAPI does not inspect each request.
Can I swap the model ID without changing the request body?
The task lifecycle is shared; the body is not. Each endpoint publishes its own JSON Schema and the API validates against that, so this is the list to reconcile before a switch.
How to choose
Kling 4.0 supports a high-resolution option.
Compare
The model identifiers are kling/4.0/image-to-video and bytedance/seedance-2.0-fast/image-to-video, and both go in the same field of the same request.
Both run the same way: submit the task, then poll it or take the callback. Queueing and retry logic carry over unchanged.
Both use the same submit-and-track flow, but their required inputs may differ. Check each model page before switching.
One key, one balance, one set of spend caps. Both bill to the same account in US dollars, and the per-key daily, monthly and lifetime limits apply to whichever one you call.
Questions developers ask
The two bill on different tiers, so there is no like-for-like row: Kling 4.0 starts at $0.216 / output seconds and Seedance 2.0 Fast at $0.045 / output seconds. Prices may change; check the estimate shown for your actual settings before submitting.
Kling 4.0 allows 60 minutes per task and Seedance 2.0 Fast allows 120. Those are ceilings rather than typical times — most requests finish far sooner — but they are what your own client timeout has to survive.
Prices and capabilities shown here come from the current public model catalogue. Check each model page for its latest inputs and examples.