What is Veo3.1 Fast?
Veo3.1 Fast is a video generation model available on UniAll AI under the public model id `veo3.1-fast-video-720p`. It is designed for faster turnaround on short AI-generated clips while supporting multiple production workflows: text-to-video, image-to-video, first/last-frame generation, reference media to video, and video extension or editing from a source video.
The model is useful when speed and iteration matter: creative testing, social media assets, e-commerce product demos, storyboards, ad variations, and automated content pipelines.
Core capabilities
- **Text to video**: generate a short clip from a written prompt.
- **Image to video**: animate a reference image with camera movement, scene action, or product motion.
- **First/last frame video**: provide a starting frame and ending frame to guide the transition.
- **Video to video**: use a source video for editing or continuation-style workflows.
- **Reference media to video**: guide the generation with reference assets.
- **Async API**: submit a job, poll or retrieve results when complete.
- **Optional audio**: enable audio generation when supported by the selected resolution profile.
Supported durations are **4s, 6s, and 8s**. The model supports **16:9** and **9:16** aspect ratios, with selectable output resolutions including **720p, 1080p, and 4K** profiles.
Who should use it?
Veo3.1 Fast is best for:
1. **Marketing teams** testing many short video concepts quickly. 2. **E-commerce operators** creating product reveal clips and lifestyle demos. 3. **Developers** adding AI video generation to SaaS tools, CMS platforms, or automation workflows. 4. **Agencies** producing fast drafts before final creative refinement. 5. **Short-video creators** generating vertical clips, storyboards, or motion concepts.
If you need the highest possible final-detail output, you may compare it with standard Veo3.1 variants. If you need lower latency and lower per-second cost for iteration, Veo3.1 Fast is usually the practical starting point.
API usage
Endpoint:
```http POST /v1/videos/generations ```
Generation is asynchronous. Send a request with the model id, generation mode, prompt, duration, and media inputs required by the selected mode.
Example text-to-video request:
```json { "model": "veo3.1-fast-video-720p", "generation_mode": "text_to_video", "prompt": "A cinematic product reveal of a matte black smart speaker on a glass table, soft studio lighting, smooth dolly-in camera movement.", "duration": 8, "aspect_ratio": "16:9", "resolution": "720p", "generate_audio": true, "video_count": 1 } ```
Example image-to-video request:
```json { "model": "veo3.1-fast-video-720p", "generation_mode": "image_to_video", "prompt": "Animate the product with a slow rotating camera, subtle reflections, premium commercial style.", "image_url": "https://example.com/product.png", "duration": 6, "aspect_ratio": "9:16", "resolution": "720p" } ```
Common generation modes:
| Mode | Required inputs | Typical use case | |---|---|---| | `text_to_video` | `prompt` | Generate a clip from text | | `image_to_video` | `prompt`, `image_url` | Animate a product, character, or scene image | | `first_last_frame` | `prompt`, `first_image_url`, `last_image_url` | Control start and end frames | | `video_to_video` | `prompt`, `video_url` | Edit or extend a source video | | `reference_media_to_video` | `prompt` | Generate using reference media context |
Pricing angle
UniAll AI bills Veo3.1 Fast by generated video seconds. The listed user price for the 720p fast profile starts at **$0.068 per second** without audio and **$0.102 per second** with audio. Higher resolution and audio profiles may cost more; for example, 4K fast generation is priced higher than 720p.
Because billing is per second, cost is easy to estimate:
```text estimated cost = duration in seconds × selected resolution/audio unit price ```
For teams running automated workflows, this makes it practical to control cost by limiting duration, choosing 720p for drafts, and reserving 4K for final assets.
Implementation tips
- Use **short, visual prompts** with subject, motion, camera direction, lighting, and style.
- Choose **9:16** for TikTok, Reels, Shorts, and mobile-first ads.
- Choose **16:9** for website hero videos, YouTube, and product landing pages.
- Use image-to-video when brand or product consistency matters.
- Use first/last-frame mode when you need a specific transition or storyboard beat.
- Handle async status and failed jobs gracefully; UniAll AI supports refund-on-failure behavior for this model.
常见问题
What is the public model id for Veo3.1 Fast API?
The public model id is `veo3.1-fast-video-720p`. Use it in the `model` field when calling the UniAll AI video generation endpoint.
What generation modes does Veo3.1 Fast support?
It supports text-to-video, image-to-video, first/last-frame video generation, reference media to video, and video-to-video workflows such as editing or extension.
How is Veo3.1 Fast priced?
It is billed per generated second. The 720p fast profile starts at $0.068 per second without audio and $0.102 per second with audio. Final cost depends on duration, resolution, and whether audio is enabled.