Kling 4.0 is Kuaishou's fourth-generation Kling video model, announced on September 28, 2026: 3–30 second clips up to 4K, up to 10 keyframes, and up to 15 references per shot. The full Kling 4.0 launches in October; Kling 4.0 Flash is in early access now. Kling 4.0 is coming to reAPI; Kling 3.0 is live today.
Kling 4.0 is the fourth generation of Kuaishou's Kling video model. Kling announced it in a September 28, 2026 release note, which says the full Kling 4.0 will officially launch in October and that Kling 4.0 Flash, the faster tier, opened to a limited early-access group the same day. The official spec sheet lists text-to-video, image-to-video, first and last frames, up to 10 keyframes, Omni Reference with up to 15 references, 3–30 second clips, 720p, 1080p, and 4K, 10-bit HDR at 1080p and 4K, and two-channel stereo audio. As of October 1, 2026, Kling's API changelog has no Kling 4.0 entry, so there is no public API for it yet.
Real-world workflows and production use cases you can build and ship with this model.
Kling 3.0 tops out at 15 seconds per clip. Kling 4.0 generates 3–30 seconds natively, and Kling says video extension up to 2 minutes is coming. A full product demo or scene fits in one generation instead of two or three stitched clips.
Kling 4.0 supports first and last frames plus multi-keyframe control with up to 10 keyframe images. You pin where the shot starts, where it passes, and where it lands, and Kling 4.0 fills the motion between them.
It takes up to 15 references in one generation: up to 10 images, up to 5 videos with a combined 30 seconds, and up to 7 elements, plus voice references. That is the part to watch for brand mascots, recurring characters, and series content.
Kling 3.0 is live on reAPI now at /models/kling-3-0: text-to-video, image-to-video, multi-shot, native audio, up to 4K. Ship on it today and move to Kling 4.0 when it can be called.
Your reAPI key already covers Kling, Seedance, Veo, Wan, and the rest. When Kling 4.0 goes live, it is a new model id on the same /api/v1/videos/generations endpoint, not a new vendor account.
reAPI bills by the second of output, and credits never expire. Kling 4.0 rates will be posted on this page at launch; Kuaishou has not published API pricing for Kling 4.0, and its current API packages do not cover Kling 4.0.
Kling 3.0 values are from the live model on reAPI. Kling 4.0 values are from Kling's official September 28, 2026 release note; the model is not yet available through an API.
Kling 4.0 values are from Kling's official release note and may change once an API ships. This table will be updated with API parameters at launch.
Sign up and create a key in the dashboard, no card required. The same key will work for Kling 4.0 at launch.
OpenWire up /api/v1/videos/generations with model kling-3-0 today. The request and task flow will be the same for Kling 4.0.
OpenWhen Kling 4.0 goes live, change the model to kling-4-0. Final parameters and per-second rates will be posted here on launch day.
Opencurl -X POST https://reapi.ai/api/v1/videos/generations \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "kling-4-0",
"prompt": "A lighthouse keeper climbs a spiral staircase at dawn"
}'Rejected synchronously with the failing field named. Check enum values, ranges, and URL fields — nothing is charged.
401 means a missing or invalid Bearer key; 402 means the reserve exceeds your balance. Manage keys and credits in the console.
Reference material and outputs pass automated moderation. Rejected tasks fail with a clear error and a full refund.
A task that reaches a failed state is never charged — the reserve refunds automatically. Keep the task id and retry when ready.
Common questions about this model.
Guides
Kling 4.0 Flash is in early access, but is there a Kling 4.0 Flash API? What Kling's API docs, price sheets, and changelog show, and what to build on today.
Comparisons
A Kling 4.0 Flash review roundup: what early testers praise (motion, voices, 20s clips), what breaks (music, shot cuts, wide shots), and how it compares.
Guides
The Kling 4.0 release date is October 2026, with Kling 4.0 Flash in early access since September 28. Official specs vs the leak, and when the API arrives.
Guides
Kling 3.0, 3.0 Omni, 3.0 Turbo, O1, 2.6, and 2.5 Turbo compared on duration, resolution, audio, and references, plus which Kling model fits each job.
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