MiniMax H3 Fast API: AI Video with Audio

Name: MiniMax H3 Fast API - AI Video Generation
Brand: MiniMax
Availability: InStock

Updated 4 Nov 2026

What is MiniMax H3 Fast?

MiniMax H3 Fast is the quick-turnaround variant of MiniMax H3: a job returns in about 30 seconds. It renders 480p or 768p video at 24 fps with native audio, runs 4 to 15 seconds per generation, and takes the same inputs as H3: text alone, a start frame with an optional end frame, 1 to 9 reference images, up to 3 reference videos, and up to 3 reference audio clips alongside images or videos. Reference images carry no per-image charge on this variant. A seed is optional; there is no prompt expansion level.

Key features of MiniMax H3 Fast

About 30 seconds a job

A 5-second render comes back in roughly 30 seconds, which makes prompt iteration a loop of attempts rather than a queue. Final renders at 2K still go to H3.

480p or 768p output

Choose 480p for the cheapest drafts or 768p for publishable social video. Resolution and aspect ratio are selected independently for text and reference generation; with a frame image, output follows the input frame shape.

Reference-to-video with no per-image charge

Pass 1 to 9 reference images and name them in the prompt as @Image1 through @Image9. All nine are included in the per-second price. Reference images cannot be combined with start/end frames in one request.

Reference videos and audio

Up to 3 reference videos in video_urls and up to 3 audio clips in audio_urls, 15 seconds in total across both. Each second of uploaded video is billed; audio is free and needs reference images or videos in the same request.

Native audio and a seed

Output arrives with an audio track generated alongside the picture. Set a seed to repeat a result with the same inputs.

What MiniMax H3 Fast is best for

Reference-heavy shots
Nine reference images cost nothing extra here, where H3 and H3 Max bill the images past their included count.
Fast prompt iteration
Try ten framings in the time one slower render takes, then send the keeper to H3.
Social video with sound
768p with native audio at a per-second rate built for batches.
Reference-driven motion and sound
A reference video carries its motion, a reference audio clip its sound, into a new shot.

MiniMax H3 Fast use cases

Lock a character, a product, a location and a style with several reference images at once without a per-image charge. Run a prompt through H3 Fast at 480p until the framing is right, then render the final version on H3 at 2K. Produce a week of 9:16 social videos with sound in one batch at 768p. Pass a short reference video and an audio clip to carry their motion and sound into a new shot.

MiniMax H3 Fast limitations

H3 Fast caps at 768p; for 2K output use MiniMax H3. It takes a seed but no prompt expansion level; MiniMax H3 Max has both. Reference images and frame images are mutually exclusive in one request, an end frame needs a start frame, and reference audio needs reference images or videos. Duration is capped at 15 seconds per generation and reference videos plus audio at 15 seconds in total.

MiniMax H3 Fast API examples

Call MiniMax H3 Fast from any language by POSTing to /v1/tasks. Full parameter docs live at docs.unifically.com/models/video/minimax/hailuo.

curl -X POST https://api.unifically.com/v1/tasks \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "hailuo/minimax-h3-fast",
    "input": {
      "prompt": "A slow dolly shot across a rain-soaked neon street, reflections rippling in the puddles",
      "aspect_ratio": "16:9",
      "resolution": "768p",
      "duration": 5
    }
  }'

Successful submission returns a task_id. Poll GET /v1/tasks/<task_id> or set a callback_url on the request to receive the finished result.

FAQs