Grok Imagine 1.5 Fast Video API

2026년 10월 18일 업데이트

What is Grok Imagine Video?

The model key is xai/grok-imagine-1.5-fast-video. It was renamed from xai/grok-imagine-video on 18 October 2026; the old key is rejected with a message naming the new one, and parameters and prices did not change.

Grok Imagine Video is a speed-optimized build of Grok Imagine 1.5 Video, the same model as the 1.5 Video API route, tuned for faster results in exchange for a small amount of quality. xAI's own figure is a 6-second 720p video in about 25 seconds.

It is also the more flexible build in every direction except resolution. Pass prompt alone for text-to-video, or supply either a single start_image_url or 1 to 7 image_urls for image-to-video, never both in the same request. Sound generates in the same pass. It is the only Grok Imagine route with style presets, with @ImageN referencing, and the only one whose videos can be extended or upscaled. On the Arena image-to-video board it still ranks ahead of every Veo 3.1 variant.

Key features of Grok Imagine Video

What Grok Imagine 1.5 Fast Video is best for

• Text-to-video from a brief

  Generate a video from a prompt alone when there is no source image to work from.

• Choreographed two-subject shots

  Put a subject into a scene explicitly: "@Image1 walks through @Image2" beats describing both from scratch.

• Multi-reference brand spots

  Separate product, talent, and background across up to 7 references, then direct them by name.

• Fast iteration on direction

  Explore camera, pacing, and composition with quick turnarounds before committing.

• Sequences past 30 seconds

  Generate an opening here, then chain Extend in 6 or 10-second steps.

• Preset-driven styling

  Reach for Spicy, Fun, or Normal when the look matters more than a precisely worded prompt.

Grok Imagine 1.5 Fast Video use cases

Referencing assets is what sets this build apart. Upload a dancer and a stage, then prompt "@Image1 does a slow dance in @Image2", and the model knows which upload is the subject and which is the scene instead of guessing from a description. A brand team can lock a product, a presenter, and a backdrop across three references and direct them by name in one call, with a matching sound bed generated alongside.

Because Extend and Upscale only accept task IDs from this route, it is also the entry point for anything longer or sharper than one pass: generate here, chain Extend for length, then Upscale the result you keep. The alternative path is to settle the opening frame here and re-animate it on 1.5 Video at 1080p.

Grok Imagine 1.5 Fast Video limitations

Output stops at 720p; 1080p is only on the 1.5 Video API build. Being speed-optimized, it trades a small amount of quality against that build at the same prompt. A single pass caps at 30 seconds, so going longer means chaining Extend. Negative prompts are ignored, so describe what you want rather than what to avoid. A start image and reference images are mutually exclusive: send one field or the other, never both, and image_urls accepts a maximum of 7.

Grok Imagine Video vs Grok Imagine 1.5 Video

Pick this build for NSFW, presets, characters, 30 second clips, or extend and upscale by task ID. Pick 1.5 Video for the API's control set: 14 references, end frame, keyframes, voices and native 1080p, safe-for-work.

Grok Imagine 1.5 Fast Video API examples

Call Grok Imagine Video from any language by POSTing to /v1/tasks. Full parameter docs live at docs.unifically.com/models/video/xai/grok-imagine-1.5-fast-video.

Text-to-video with referencing assets. @Image1 and @Image2 point at the uploads by position:

curl -X POST https://api.unifically.com/v1/tasks \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "xai/grok-imagine-1.5-fast-video",
    "input": {
      "prompt": "@Image1 does a slow dance in @Image2. AUDIO: soft rain, distant thunder",
      "aspect_ratio": "9:16",
      "duration": 10,
      "resolution": "720p",
      "video_preset": "normal",
      "image_urls": [
        "https://files.unifically.com/your-dancer.png",
        "https://files.unifically.com/your-stage.png"
      ]
    }
  }'

For a plain image-to-video request, send start_image_url instead, never alongside image_urls:

curl -X POST https://api.unifically.com/v1/tasks \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "xai/grok-imagine-1.5-fast-video",
    "input": {
      "prompt": "The camera pushes in as the city lights blur behind her.",
      "aspect_ratio": "16:9",
      "duration": 10,
      "resolution": "720p",
      "start_image_url": "https://files.unifically.com/your-opening-frame.png"
    }
  }'

Successful submission returns a task_id. Poll GET /v1/tasks/<task_id> or set a callback_url on the request to receive the finished video URL. That same task_id is what Extend and Upscale take.

Grok Imagine 1.5 Fast Video 가이드 및 비교

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Grok Imagine 1.5 Fast Video API pricing

Grok Imagine API pricing from $0.01 per image on UnificAlly, plus video cost per second. Compare every route, common jobs, and the right model ID.

Grok Imagine 1.5 Fast Video API pricing 읽기→