Kling 4.0kling-4.ai Docs
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Getting Started

Overview

API Reference

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Models

Which model strings the API accepts today, and how the kling-4-0 upgrade will work when it ships.

Available now

Model stringStatusNotes
kling-v2-6DefaultThe current production Kling model on our pipeline. Used when model is omitted.

kling-v2-6 supports everything documented in Generate a Video: std/pro modes, 5s/10s durations, three aspect ratios, native audio (pro), negative prompts, and up to two reference images (end-frame control in pro).

Kling 4.0 at launch

Kuaishou has not announced an official Kling 4.0 release date — we track the signals in the release-date post. When it ships on our platform, it arrives as a new model string, and upgrading is a one-field change:

 {
-  "model": "kling-v2-6",
+  "model": "kling-4-0",
   "prompt": "…",
   "parameters": { … }
 }

Everything else — auth, endpoints, job lifecycle, response shape — stays the same. That's the point of the job-based design: model generations change, the integration doesn't.

Requests with a model string the API doesn't recognize fail with 400 INVALID_INPUT, so you can deploy the new string the moment we announce availability and not before.

Which mode should you use?

  • std — cheaper and faster; text-to-video and single-reference work. Good for iteration: find your prompt in std, then re-render the keeper in pro.
  • pro — higher render quality, plus the pro-only features: native audio and two-image end-frame control.

For prompt technique — shot lists, camera language, film-stock grading — see the multi-shot prompt guide.

Table of Contents

Available now
Kling 4.0 at launch
Which mode should you use?