MiniMax H3 Max API

Introduction

MiniMax H3 Max Text to video turns a written prompt into a clip of 5 to 15 whole seconds at 480p or 768p, with ambience, foley and music generated in the same pass. MiniMax describes H3 Max as the fast-generation variant of H3.

Choose a MiniMax H3 Max mode by starting material

Key features

Six frame shapes, square by default

aspect_ratio accepts 21:9, 16:9, 4:3, 1:1, 3:4 and 9:16, and it defaults to 1:1, so a widescreen brief sent without the field comes back square. The snow-train-window-hands example is built for 21:9: a train crossing the full width of the frame while two hands meet on either side of the carriage glass, a composition that does not survive being cropped squarer.

480p for drafts, 768p for the keeper

resolution takes 480p or 768p and defaults to 768p. There is no 720p, 1080p or 4K option, and the schema rejects those values before the request is queued.

Prompt expansion is opt-in

enable_prompt_expansion is off by default, so the prompt is rendered as written.

Request parameters

Pricing

Prices are in credits, the same credits you use on the website (1 credit = $0.01). The hold is taken when the task is accepted and settled to the actual charge when it finishes; failed tasks are refunded.

Each task is rounded up to whole credits, so one run at the lowest tier costs 38 credits for a 5-second clip ($0.38).

For an exact number before you run, send the same body to POST /jobs/quote.

Use cases

Fashion and campaign motion

The silver-corridor example is a campaign-style shot built from one paragraph: a liquid-silver gown catching hard rim light, hair moving in a wind machine and a final look straight down the lens, at 21:9 for five seconds with a low synth drone in the audio. Fabric movement, light and the closing look are all written; none of them was supplied as an image.

Period looks asked for by name

Film-stock character can be requested directly. The roller-rink example asks for a 1970s look with heavy halation, faded colour, thick grain and slight gate weave, and fits a two-part action into five seconds: a slow lap of the rink, then a backwards coast toward camera with arms spread wide.

Material and light studies

Scenes where several surfaces react to moving light suit a written brief. Use a brief like this to check whether a lighting idea reads before you build source frames for image-to-video.

Prompt guide & pro tips

Write the shot in chronological order

List subject, movement, camera, light and sound in the order they happen. The silver-corridor prompt walks through the shot from the first step to the final look, then adds the image quality ("anamorphic 2.39:1, deep blacks, glossy specular highlights") and closes with the sound ("low synth drone").

State the boundaries as well as the action

If you switch expansion on, write what must stay fixed as well as what should happen. Prose leaves wardrobe, body and framing to the model, so consecutive runs drift unless those details are written down.

Switch to image-to-video for a literal result

When a take gets the idea right but the subject is not exactly as designed, generate or choose a still and move to image-to-video: an opening frame is followed far more closely than the same description in a prompt. Keep the duration deliberate too, since omitting it gives 8 seconds, not 5.

API quick start

Call the MiniMax H3 Max API in three steps

1. Create an API key. Sign in to PopNow and create a key in the API console. Keys start with sk-popnow- and use the same credits as the website.
2. Send the request. POST /jobs/createTask with model minimax/h3-max/text-to-video and an input object that follows the parameter table. The response returns a task ID straight away.
3. Get the result. Poll GET /jobs/recordInfo with the task ID, or pass a callBackUrl and we post the result to it. Download the output links when the task succeeds.

# 1. Create the task. Keep the Idempotency-Key if you retry after a network error.
export IDEMPOTENCY_KEY="$(uuidgen)"
curl -X POST https://api.popnow.ai/api/v1/jobs/createTask \
  -H "Authorization: Bearer $POPNOW_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $IDEMPOTENCY_KEY" \
  -d '{
  "model": "minimax/h3-max/text-to-video",
  "input": {
    "prompt": "A slow aerial shot drifting over a misty pine forest at sunrise",
    "aspect_ratio": "1:1",
    "duration_seconds": 8,
    "resolution": "768p"
  }
}'

# 2. Copy data.taskId from the response, then poll until state is succeeded, failed, canceled or expired.
TASK_ID="TASK_ID_FROM_RESPONSE"
curl "https://api.popnow.ai/api/v1/jobs/recordInfo?taskId=$TASK_ID" \
  -H "Authorization: Bearer $POPNOW_API_KEY"

Replace the prompt and any links with your own. The API tab has the response, polling and callback reference.

MiniMax H3 Max API questions

All MiniMax models

MiniMax H3 adds reference-to-video and a 2K tier. Max is the quicker option when 768p is enough.

• MiniMax H3 APIExpressive clips with audio, up to 2KFrom 28 credits for a 5-second clip
• MiniMax Speech 2.8 HD APIHigh-fidelity speech in 400+ voices with emotion controlFrom 18 credits per 1,000 characters
• MiniMax Music 3.0 APIFinished stereo songs, with vocals or instrumentalFrom 27 credits per run
• MiniMax H3 Singularity LoRA APICommunity-tuned H3 video that loads your own LoRAsFrom 45 credits for a 5-second clip
• MiniMax H3 Max APIFast clips with ambience, effects and musicFrom 38 credits for a 5-second clip
• MiniMax H3 LoRA APIMiniMax H3 video with sound and up to three of your LoRAsFrom 38 credits for a 5-second clip
• MiniMax H3 Image LoRA APIH3 stills and edits with up to three of your LoRAsFrom 7 credits per image
• MiniMax Speech 2.8 Turbo APIFast speech in 400+ voices with emotion controlFrom 11 credits per 1,000 characters

Other video APIs

• Seedance 2.5 APIByteDance's newest: 30-second clips with native audioFrom 56 credits for a 5-second clip
• Kling 3.0 API4K clips, multi-shot cuts and motion controlFrom 51 credits for a 5-second clip
• Vidu Q4 Preview APIUp to 4K clips with sound and spoken dialogueFrom 34 credits for a 5-second clip
• Wan 3.0 APIUp to 30-second clips with synced audioFrom 34 credits for a 5-second clip
• Kling O3 APIKling’s unified model: create, animate, reference and edit up to 4KFrom 51 credits for a 5-second clip
• LTX 2.5 APILong 20-second takes up to 4K with a soundtrackFrom 68 credits for a 5-second clip

More about MiniMax H3 Max

Try it

MiniMax H3 Max AI Video Generator onlineCreate videos with MiniMax H3 Max in PopNow

Docs

MiniMax H3 Max model ID and input schema in the API docsPopNow API quickstart: your first request in five minutesImage to video guide for the PopNow APIWebhooks: get MiniMax H3 Max results without polling