Veo3.1 Video Extend | AI Video Extension API

Veo 3.1 — Video Extend

Veo 3.1 Video Extend lets you take an existing Veo-generated clip and seamlessly append a new 7-second continuation. You pass the previous output as video plus a new prompt, and the model returns one merged file that contains both the original segment and the extension.

⭐ Why this endpoint is special

True continuation, not a restart – So style, motion and framing stay consistent.
Fixed extension unit – Each call adds +7 seconds of new footage; you can chain up to 20 extensions in a row.
Single merged result – The API returns one video (original + new part) with a maximum length of 148 seconds.
Tight input constraints – Only approved aspect ratios, resolutions and durations are accepted, which keeps the continuation stable and predictable.

🎯 Best for

Storytelling & cinematic beats – Add “what happens next” to a strong shot without regenerating the whole sequence.
Marketing & product videos – Test extra scenes, alternative endings, or extended hero shots from a proven base clip.
Social workflows – Build longer Shorts/Reels/TikToks by stacking 7-second chunks while keeping visual continuity.

🧩 Inputs & Constraints

Required inputs

video* – A clip you previously created (URL or upload). The Veo 3.1 generation result will be better!
prompt* – Text describing what should happen in the next 7 seconds: action, camera, mood, continuity cues (character, setting, lighting, etc.).

Strict requirements

Input source – The input must be originally produced by Veo 3.1.
If you try to extend non-Veo footage, the request may fail or produce video without proper audio.
Input limits
Max input duration: 141 s
Aspect ratio: 16:9 or 9:16
Resolution: 720p or 1080p

Extension limits

Each call adds +7 s to the input clip.
Up to 20 chained extensions are supported.
Max total output length (original + extensions): 148 s.

Output: a single MP4 video at the same aspect ratio / resolution as the input, containing the entire extended sequence.

🚀 How to Use

Generate a base video with Veo 3.1 text-to-video or image-to-video.
Take that output and pass it to Veo 3.1 Video Extend as video.
Write an extension prompt that describes the next beat (e.g. change in camera, action, mood, or environment).
Submit the job and download the merged extended clip.
Repeat with the new output as input if you want to continue the story (up to the 148-second max).

💡 Prompt Tips

Write prompts like a “next shot” description: action + camera + mood + continuity anchors “Continue from the previous scene, camera slowly dollies forward, the character steps into the light, warm sunset tones, soft lens flare.”
Mention what should stay the same (main subject, time of day, general lighting) to keep continuity strong.
If audio continuity matters, ensure the last second of the input clip has clean, usable audio; the extension will build from that context.
Plan your script around the 7-second extension unit and the 148-second hard cap.

💰 Pricing

Flat price: $2.80 per run (each call adds one 7-second extension and returns a merged video).

Whether your clip is 20 seconds or 140 seconds long, each additional +7 s extension costs $2.80.

🔁 More Model Options

/wan-2.5/video-extend Extend WAN 2.5 AI videos with smooth, style-consistent continuations, perfect for story-driven ads, trailers, and long-form generative video workflows.
google/veo3.1-fast/video-extend Google Veo 3.1 Fast video extend rapidly adds high-quality extra segments to Veo-generated clips, ideal for Shorts, Reels, and other fast-turnaround AI video content.

Veo3.1 Video Extend API — Quick start

Grab a WaveSpeedAI API key, then call POST https://api.wavespeed.ai/api/v3/google/veo3.1/video-extend with your input as JSON. The endpoint returns a prediction id; poll the prediction endpoint until status flips to completed, then read the output URL from data.outputs[0]. Examples for Veo3.1 Video Extend below.

HTTP example

# Submit the prediction
curl -X POST "https://api.wavespeed.ai/api/v3/google/veo3.1/video-extend" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $WAVESPEED_API_KEY" \
  -d '{
    "video": "https://example.com/your-input.mp4",
    "prompt": "A cinematic shot of a city at sunset, soft golden light",
    "resolution": "1080p",
    "negative_prompt": "blurry, low quality, distorted",
    "seed": 0
}'

# Response includes a prediction id. Poll for the result:
curl -X GET "https://api.wavespeed.ai/api/v3/predictions/{request_id}/result" \
  -H "Authorization: Bearer $WAVESPEED_API_KEY"

# When status is "completed", read the output from data.outputs[0].

Node.js example

// npm install wavespeed
const WaveSpeed = require('wavespeed');

const client = new WaveSpeed(); // reads WAVESPEED_API_KEY from env

const result = await client.run("google/veo3.1/video-extend", {
        "video": "https://example.com/your-input.mp4",
        "prompt": "A cinematic shot of a city at sunset, soft golden light",
        "resolution": "1080p",
        "negative_prompt": "blurry, low quality, distorted",
        "seed": 0
});

console.log(result.outputs[0]); // → URL of the generated output

Python example

# pip install wavespeed
import wavespeed

output = wavespeed.run(
    "google/veo3.1/video-extend",
    {
    "video": "https://example.com/your-input.mp4",
    "prompt": "A cinematic shot of a city at sunset, soft golden light",
    "resolution": "1080p",
    "negative_prompt": "blurry, low quality, distorted",
    "seed": 0
}
)

print(output["outputs"][0])  # → URL of the generated output

Veo3.1 Video Extend API — Frequently asked questions

What is the Veo3.1 Video Extend API?

Veo3.1 Video Extend is a Google model for video extension, exposed as a REST API on WaveSpeedAI. Extend and continue Veo 3.1 videos with smooth motion, preserved style, and strong scene coherence. Ready-to-use REST inference API, best performance, no coldstarts, affordable pricing. You can call it programmatically or try it from the playground above.

How do I call the Veo3.1 Video Extend API?

POST your input parameters to the model's REST endpoint (shown in the API tab of this playground) with your WaveSpeedAI API key in the Authorization header. Submission returns a prediction ID; poll the prediction endpoint until status flips to "completed", then read the output URL from the result. The playground generates a ready-to-paste code sample in Python, JavaScript, or cURL for whatever inputs you've set. Full request/response shape is documented at https://wavespeed.ai/docs/docs-api/google/google-veo3.1-video-extend.

How much does Veo3.1 Video Extend cost per run?

Veo3.1 Video Extend starts at $2.80 per run. That figure is the base price — the final charge scales with the parameters you set in the form (output size, length, count, references, or whatever knobs this model exposes), so a higher-quality or larger output costs more than a minimal one. The exact cost for your current input is shown live next to the Generate button before you submit, and the actual per-call charge is recorded on the prediction afterwards.

What inputs does Veo3.1 Video Extend accept?

Key inputs: `prompt`, `video`, `resolution`, `seed`, `negative_prompt`. The full JSON schema (types, defaults, allowed values) is rendered above the Generate button and mirrored in the API reference at https://wavespeed.ai/docs/docs-api/google/google-veo3.1-video-extend.

How long does Veo3.1 Video Extend take to generate?

Average end-to-end generation time on WaveSpeedAI is around 140 seconds per request — measured across recent runs. Queue time scales with global demand; live status is visible in the prediction record.

Can I use Veo3.1 Video Extend outputs commercially?

Commercial usage rights depend on the model's license, set by its provider (Google). The license summary appears on the model card above; see WaveSpeedAI's Terms of Service for platform-level conditions.

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