Kling 4.0 Extend Video: Continue a Clip Past Its Ending
Last verified: October 29, 2026
Kling 4.0 continues an existing video with new footage that stays connected to the original scene, so the action on screen keeps going instead of restarting as a new shot. With Kling 4.0 Extend Video you upload the clip in the Video slot and write what happens after its final frame in the Prompt box. Then you choose how many seconds to add with Video Duration. If you already know the closing image, add it under Last Frame (optional).
The take you already have stays the anchor. You don't re-roll a whole scene to get a few more seconds. You start from footage that already works, and the extension begins at its last frame, so the ending you upload is where the new material starts. Use it when a shot is good but stops too soon: a reaction that needs a beat longer, a walk that should reach the door, or a reveal the cut never got to.
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Extension Inputs and Output at a Glance
What goes into a Kling 4.0 extension run and what comes back.
Input
Video (MP4 or MOV, up to 50 MB) + Last Frame (optional) (JPG, JPEG, PNG or WEBP, up to 10 MB) (optional) + a text prompt of up to 5,000 characters
Video Duration
3 to 30 seconds
Resolution
720P or 1080P
Output
1 video per run
How Do I Make the New Seconds Match My Clip?
Prompt the Continuation, Not a Recap
Size Video Duration to the Beats That Follow
How Do I Extend a Video with Kling 4.0?
Six steps take you from an uploaded clip to a downloaded extension.
When to Extend Instead of Regenerating or Editing
Extending is one of several ways to get the shot you need from Kling 4.0. Here is when each one fits.
| Criterion | Kling 4.0 | Alternatives | Best For |
|---|---|---|---|
| Where the shot starts | You start from footage you already have, and the new seconds begin at your clip's last frame. | A new Kling 4.0 generation starts from a prompt or an image, optionally combined with several creative references. | Pick the extension when an existing take is worth keeping, and a fresh generation when the shot hasn't been made yet. |
| Fixing specific moments | An optional Last Frame image gives the continuation a closing picture to work toward, while the prompt covers everything in between. | Kling 4.0 keyframe generation accepts up to 10 keyframe inputs to set character states, scene changes and story beats along the way. | Use Last Frame when only the ending has to be exact, and keyframes when several moments inside the shot must land precisely. |
| Changing what is on screen | The extension adds seconds after your footage, and your prompt decides what happens in them. | Kling 4.0 video editing adds, removes or replaces subjects and scene elements in existing footage using prompts and visual references. | Extend when the content is right but the shot ends too soon, and edit when something already in the footage needs to change. |
Fixes for Common Extension Problems
What usually goes wrong before or at the start of an extension, and how to fix it.
The upload won't accept my video.
The extension starts from a black frame, a fade-out or an end title.
My Last Frame image gets rejected.
Frequently Asked Questions
Which videos and images can I upload to extend?
Video is required and takes an MP4 or MOV file of up to 50 MB and up to 30 seconds long. Any clip that fits those limits works, whether you shot it, edited it or generated it elsewhere. Last Frame (optional) takes a JPG, JPEG, PNG or WEBP image of up to 10 MB that is at least 300×300 pixels.
Do I have to write a prompt, or will Kling 4.0 continue the clip on its own?
You need a prompt. Prompt is a required field here, so every run starts with a written description of the continuation. When the clip's action is obvious, a sentence or two about how it ends is enough. Write more when the new seconds need to go somewhere the footage doesn't already suggest.
What makes one extension cost more than another?
The credit cost of a run is calculated from the options you choose. It appears above the Generate button once you're signed in. It changes with Video Duration and Resolution, so changing either one updates the figure before you run.
Can I keep extending a clip toward two minutes?
Kling's feature pages describe Video Extension as supporting multiple continuation passes that reach a total length of up to two minutes.
Kuaishou's launch announcement says the extension feature will soon support multiple extensions of up to two minutes. Here, each run extends one clip uploaded in Video, and that clip has to fit the upload limits above.