AI video models · compared
Kling 4.0 vs Kling v3
Kling 4.0 and Kling v3 are both AI video models that run on one varg API key. This page puts what the varg catalog states about each side by side: the price, how it is billed, the limits of the input, what it takes and the typical time. It ranks neither on quality.
- Kling 4.0
- From $0.48 per run from $0.157/s
- Kling v3
- From $0.56 per run from $0.112/s
Every model is billed at its provider's price with no markup, from one credit balance: 1 credit is $0.01.
Kling 4.0 vs Kling v3: side by side
Every row is read from the varg catalog and each model's input schema. A "from" price is the cheapest request the catalog states for that model, at its own cheapest settings. For the exact price of a request, send its body to POST https://api.varg.ai/v2/estimate.
| Fact | Kling 4.0 | Kling v3 |
|---|---|---|
| Made by | Kuaishou | Kuaishou |
| Takes and makes | Text to video, Image to video, Video to video | Image to video, Reference to video, Text to video |
| Price | From $0.48 per run | From $0.56 per run |
| Rates on the cheapest route | Resolution 1080p: $0.235/s; Other: $0.157/s; Minimum charge: $0.471 | Audio on: $0.168/s; Other: $0.112/s; Minimum charge: $0.56 |
| Billed | per second | per second |
| Clip length | 3 to 30 s | 3 to 15 s |
| Resolutions you can set | 720p, 1080p | 4k |
| Audio switch | Yes: "audio": true asks for a native audio track | Yes: "audio": true asks for a native audio track |
| Typical time | ~3 min | ~2 min |
| Routes | 9 on fal | 4 on fal |
| Model id | kling_v4 | kling_v3 |
Which to pick
Each line is a difference between two rows of the table. None of it says which model's output looks better: that depends on the prompt.
Pick Kling 4.0 when
- you want the lower starting price: from $0.48 per run, against from $0.56 per run, each at the model's own cheapest settings.
- you need a clip longer than 15 seconds: it takes up to 30 in one request.
- you need video to video: the catalog lists a route for it on Kling 4.0, none on Kling v3.
Pick Kling v3 when
- you want the lower starting rate: from $0.112/s, against from $0.157/s; the table gives each model's rate by setting.
- you need 4k: the tiers Kling 4.0's input lists stop at 1080p.
- you want the shorter typical wait: ~2 min, against ~3 min, by the catalog's estimates.
Call Kling 4.0 and Kling v3
One endpoint and one API key for both: POST https://api.varg.ai/v2/tools/video/call with Authorization: Bearer $VARG_API_KEY. It answers 202 with a job right away; poll GET /v2/jobs/{id} until its status is completed.
Kling 4.0
curl -X POST https://api.varg.ai/v2/tools/video/call \
-H "Authorization: Bearer $VARG_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "kling_v4",
"prompt": "A detective in a black trench coat stands on a rooftop in the rain, looking through a telescope.",
"duration": 5
}'vargai call_tool --tool video '{"model":"kling_v4","prompt":"A detective in a black trench coat stands on a rooftop in the rain, looking through a telescope.","duration":5}'Kling v3
curl -X POST https://api.varg.ai/v2/tools/video/call \
-H "Authorization: Bearer $VARG_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "kling_v3",
"prompt": "a woman walking through autumn forest, golden hour, cinematic",
"files": [
{
"url": "https://example.com/cat.png"
}
],
"duration": 5
}'vargai call_tool --tool video '{"model":"kling_v3","prompt":"a woman walking through autumn forest, golden hour, cinematic","files":[{"url":"https://example.com/cat.png"}],"duration":5}'How billing works
Every model is billed at its provider's price with no markup, from one credit balance: 1 credit is $0.01. varg's fee is on the top-up, not on the run: 5.5% of the credits you buy ($0.80 at the least), or 8% for a team workspace. Pricing
Kling 4.0 vs Kling v3: questions
- Which is cheaper, Kling 4.0 or Kling v3?
- Kling 4.0 starts lower: from $0.48 per run, against from $0.56 per run for Kling v3. By starting rate, Kling v3 is lower: Kling 4.0 from $0.157/s, Kling v3 from $0.112/s. Those are each model's cheapest settings, and the price of a request depends on what it asks for: the table lists each model's rates. For the exact price of a request before you run it, send the same body to POST https://api.varg.ai/v2/estimate.
- Which makes longer clips, Kling 4.0 or Kling v3?
- Kling 4.0: up to 30 seconds in one request, against 15 for Kling v3, by their input schemas.
- Which resolutions can I set on Kling 4.0 and Kling v3?
- Kling 4.0: 720p, 1080p. Kling v3: 4k. These are the tiers the "resolution" field of each model's input schema lists; a model can also have a default size that is not one of them.
- Can I use Kling 4.0 and Kling v3 with one API key?
- Yes. Both run on varg behind POST https://api.varg.ai/v2/tools/video/call with one API key and one credit balance: send "model": "kling_v4" or "model": "kling_v3". Every model is billed at its provider's price with no markup, from one credit balance: 1 credit is $0.01.