MiniMax H3 Open Weights Land With Native ComfyUI Support
MiniMax H3 open weights are on Hugging Face with native ComfyUI support merged. Repackaged bf16, INT8, pruned, and NVFP4 files plus six official workflow templates.
MiniMax officially open-sourced H3, the omni-modal video model behind the Hailuo line, on August 3. The weights are published on Hugging Face, and native ComfyUI support landed the same day: pull request Comfy-Org/ComfyUI #15224 merged on August 3, adding joint audio-video generation with four new nodes and six official workflow templates.
H3 launched on July 31 (read the launch story). The open-weights release brings the model to local GPUs with multiple quantization options.
An example input image from MiniMax's official H3 multimodal context demo
H3-generated video combining a reference clip, an image, and an audio track in a single prompt (source: MiniMax blog)
System overview
H3 is a general-purpose omni-modal generation system built from three modules:
- H3-Context-IR: a managed preprocessing and orchestration system that parses the multimodal context (text, images, video, audio) and converts it into a structured intermediate representation for generation. It is not included in the open-source release; MiniMax provides it as an API and publishes a prompt-writing guide for building your own.
- H3-Base: the open-weight 33.1B omni transformer that generates 768p video with native stereo audio.
- H3-Regenerate-2K: regenerates the 768p output at 2K resolution in-context, reusing the original multimodal context. This module is not open-sourced yet; an API reproduces the full 2K pipeline.
The open release covers H3-Base as two task-specific checkpoints: FL2VA (text-to-video, first-frame, last-frame, and first+last-frame modes) and Ref2VA (reference-based generation from images, video, and audio).
Output specs
| Item | Spec |
|---|---|
| Duration | 4-15 seconds |
| Aspect ratios | 21:9, 16:9, 4:3, 1:1, 3:4, 9:16 |
| Resolution | Short edge 768px by default; 2K via H3-Regenerate-2K |
| Frame rate | 24 FPS |
| Audio | 32 kHz stereo, generated in the same pass |
| Languages | 11 stably supported (ar, zh, en, fr, de, it, ja, ko, pt, ru, es) |
Input modes
FL2VA accepts 0, 1, or 2 images: no image is text-to-video, one image is first- or last-frame conditioning, and two images are first+last-frame conditioning.
Ref2VA accepts up to 9 reference images, 3 reference videos (2-15 s each, 15 s total max), and 3 reference audio clips (2-15 s each, 15 s total max, always alongside an image or video). Mixed input is capped at 12 files total.
Open weights on Hugging Face
Two repositories are now live:
- MiniMaxAI/MiniMax-H3 (Hugging Face): the official release in Diffusers format, with FL2VA and Ref2VA variants, full model code, and the prompt-writing guides (base / reference). Licensed under the MiniMax H3 Community License Agreement.
- Comfy-Org/MiniMax-H3 (Hugging Face): files repackaged for ComfyUI's native nodes, ready to drop into
models/diffusion_models,models/text_encoders, andmodels/vae.
| Component | Files |
|---|---|
| Diffusion model | minimax_h3_fl2va_bf16 (61.7 GB), minimax_h3_fl2va_int8_convrot (31.7 GB), minimax_h3_fl2va_pruned_int8_convrot (19.5 GB), plus matching ref2va_* variants |
| Text encoder | qwen3vl_32b_minimax_h3_bf16 (48.0 GB), int8_convrot (25.3 GB), nvfp4_awq (14.6 GB) |
| VAEs | minimax_h3_video_vae_fp16 (4.9 GB), minimax_h3_audio_vae_fp32 (0.6 GB) |
The pruned INT8 checkpoints are about 40% smaller than the standard INT8 files thanks to precomputed adaLN curve tables, and the NVFP4 AWQ text encoder runs on any GPU. H3-Base deploys through SGLang, vLLM, diffusers, and ComfyUI.
Native ComfyUI support merged
Native support merged as Comfy-Org/ComfyUI #15224 on August 3, integrating a single-stream packed-token diffusion transformer that denoises video and stereo audio latents jointly, conditioned on Qwen3-VL-32B hidden states with per-token modality tags. Four new nodes handle the workflow: EmptyMiniMaxH3LatentAV, MiniMaxH3ImageToVideo, MiniMaxH3ReferenceToVideo, and MiniMaxH3SigmaShift.
The official text-to-video and image-to-video workflows are available as downloads:
- video_minimax_h3_t2v.json (text to video)
- video_minimax_h3_i2v.json (image to video)
- video_minimax_h3_r2v.json (reference to video)
Official workflow templates
Six official templates shipped through Comfy-Org/workflow_templates:
| Template | Mode |
|---|---|
| video_minimax_h3_t2v.json | Local: text to video |
| video_minimax_h3_i2v.json | Local: image to video |
| video_minimax_h3_r2v.json | Local: reference to video |
| api_minimax_h3_t2v.json | API: text to video |
| api_minimax_h3_r2v.json | API: reference to video |
| api_minimax_h3_flf2v.json | API: first/last frame to video |
Step-by-step guides for the local open-weights workflows are published on the official docs: MiniMax H3 open-source workflow tutorial.
Availability
- Open weights: Live on Hugging Face (MiniMaxAI/MiniMax-H3) and repackaged for ComfyUI at Comfy-Org/MiniMax-H3.
- ComfyUI: Native support merged in Comfy-Org/ComfyUI #15224; update ComfyUI to the latest version to get the new nodes.
- Official templates: Six workflows in ComfyUI's built-in template gallery.
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