---
license: other
license_name: minimax-h3-image-community-license-agreement
license_link: LICENSE
base_model:
- MiniMaxAI/MiniMax-H3-Image
base_model_relation: quantized
pipeline_tag: text-to-image
tags:
- comfyui
- diffusion-single-file
- minimax-h3
- fp8
- nvfp4
- text-to-image
- image-editing
---

# MiniMax-H3-Image fp8 scaled and NVFP4 (ComfyUI)

Two more precisions of the MiniMax-H3-Image diffusion transformer for
ComfyUI, alongside the bf16, int8 ConvRot and w4a8 files in
[Comfy-Org/MiniMax-H3-Image](https://huggingface.co/Comfy-Org/MiniMax-H3-Image).
They are drop-in replacements for those: same layout, same loader, same
workflow. GGUF versions are in
[LSDJesus/MiniMax-H3-Image-GGUF](https://huggingface.co/LSDJesus/MiniMax-H3-Image-GGUF).

> **Modified files.** These are quantized versions of MiniMax-H3-Image, made
> from Comfy-Org's `minimax_h3_image_pruned_bf16.safetensors`.
> MiniMax-H3-Image is licensed under the MiniMax-H3-Image Community License
> Agreement, Copyright © 2026 MiniMax. All Rights Reserved. See `LICENSE` and
> `NOTICE`. Among other terms, the license grants rights only outside the
> European Union, the United Kingdom, South Korea and the United States
> (sections I.5 and II), and it includes an acceptable use policy. Read it
> before downloading.

## Files

| File | Format | Size | Runs natively on | Speed |
| --- | --- | --- | --- | --- |
| `minimax_h3_image_pruned_fp8_scaled.safetensors` | fp8 e4m3, one scale per weight tensor | 21.0 GB | RTX 40 and RTX 50 | 2.1 steps/s |
| `minimax_h3_image_pruned_nvfp4.safetensors` | NVFP4 (fp4 with fp8 scales per 16 values) | 12.5 GB | RTX 50 and other Blackwell | 3.4 steps/s |

Speed is sampling at 2048×2048 on an RTX PRO 6000 Blackwell. On the same card
Comfy-Org's int8 ConvRot ran 2.6 steps/s and w4a8 2.5. On cards without
native support for a format, ComfyUI still runs it, more slowly.

## Requirements

- **ComfyUI with MiniMax-H3-Image support**, merged on 10 November 2026
  (ComfyUI 0.44).
- The text encoder (`qwen3vl_32b_minimax_h3_nvfp4_awq` or `_int8_convrot`) and
  the VAE (`minimax_h3_image_vae_fp16`) from
  [Comfy-Org/MiniMax-H3-Image](https://huggingface.co/Comfy-Org/MiniMax-H3-Image).

Put the file in `models/diffusion_models/`, open ComfyUI's **MiniMax H3
Image** template and choose it in Load Diffusion Model.

## What is quantized

The same 200 layers that Comfy-Org quantizes in its int8 and w4a8 files: the
fused `qkv_proj`, `out_proj`, `mlp.fc1` and `mlp.fc2` of the 50 transformer
blocks, 95.8% of the weights. The token refiner, the condition projection,
the adaLN time-curve basis, the patch and output projections and all norms
are kept as in the bf16 source, as are the per-block int8 attention setting
and the `config` metadata with the 6-step PDD schedule.

- **fp8 scaled**: e4m3 weights with one scale per tensor. `mlp.fc2` is tagged
  `full_precision_matrix_mult` (fp8 weights, matrix multiply in bf16), as in
  Comfy-Org's own MiniMax-H3 fp8 files. Its input has outliers that ComfyUI's
  on-the-fly per-tensor fp8 activation scale cannot hold: without the tag the
  render drifted far more than NVFP4 (the subject changed and text was
  misspelled). The other layers quantize their activations on the fly; there
  are no calibrated activation scales.
- **NVFP4**: E2M1 values with an e4m3 scale per block of 16 and one global
  scale per tensor, made with ComfyUI's comfy-kitchen quantizer.

## Quality

One render per file, seed 42, 2048×2048, 6 steps, compared with Comfy-Org's
int8 ConvRot render. Left: whole image; right: a 1:1 crop. A 6-step model
changes its composition a little with any change to the weights, so
differences in pose and layout are normal; look for broken texture and text.

The template's own prompt:

![Comparison on the template prompt](assets/compare_fox.jpg)

A held-out photographic prompt (a fruit market with signs):

![Comparison on a market prompt](assets/compare_market.jpg)