MiniMax H3’s weights are public, but the full video system is not

MiniMax publicly released the Base weights for H3 on August 3, giving developers downloadable checkpoints for its video-and-audio generation model three days after the original product launch. The official repository includes one model for text and first- or last-frame generation, and another for generation driven by reference images, videos, and audio.

ComfyUI added native support on the same day. Its version 0.30.0 release provides workflows for text-to-video, image-to-video, and reference-to-video generation, so trying H3 locally does not require assembling the entire inference pipeline by hand.

That makes H3 an open-weight video model, although “open” needs several qualifications here. The license excludes some of the world’s largest software markets, the complete 2K workflow is not available locally, and even the optimized files remain a large download.

ComfyUI cuts the local package down to 42.5 GB

MiniMax describes H3 Base as producing clips between four and 15 seconds at 24 frames per second, with 32 kHz stereo audio generated alongside the video. The default local output uses a 768-pixel short side. ComfyUI’s documented native canvas is roughly 1344×768, while its templates start with smaller preview settings to reduce generation time.

For the FL2VA workflow, the original BF16 diffusion model, text encoder, and two VAE files total about 123.6 GB. The separate ComfyUI-optimized artifact repository provides minimax_h3_fl2va_pruned_int8_convrot, the qwen3vl_32b_minimax_h3_nvfp4_awq text encoder, and the video and audio VAEs. Together, those four files are about 42.5 GB. ComfyUI attributes the reduction to pruning replaceable modulation weights, Int8 ConvRot quantization, custom kernels, and dynamic memory offloading.

That 42.5 GB figure is the size of the selected artifacts, not a VRAM requirement. ComfyUI says offloading allows H3 to run on a GPU such as an RTX 3060, but two early Reddit reports show how conditional that claim is.

One r/comfyui user with an RTX 4070 and 64 GB of system RAM reported generating a 608×352 clip at 20 steps in 167 seconds. In another hardware thread, a user with 16 GB of VRAM and 32 GB of system RAM reported crashes, while someone with the same VRAM and 64 GB of RAM said the model worked. These are individual reports rather than benchmarks, but they underline the practical role of system RAM, storage speed, resolution, model variant, and offloading settings.

The downloadable model is only the Base layer

MiniMax presents H3 as a three-part system. H3-Context-IR interprets complex combinations of prompts, images, audio, and reference video. H3 Base generates 768p audio and video. H3-Regenerate-2K then uses the original context and the Base output to produce the higher-resolution result.

Only the Base checkpoints are included in the public release. MiniMax says Context-IR depends on several hosted models and services, while Regenerate-2K has not yet been released. The initial weights also use full attention; a sparse-attention implementation is promised for a later update. Developers can therefore run meaningful H3 workflows locally, but they cannot reproduce MiniMax’s complete hosted 2K pipeline from the published files alone.

The H3 Community License is an equally important boundary. It grants rights worldwide except in the United States, European Union, United Kingdom, and South Korea. MiniMax asks people in those regions to contact the company for a separate license. Commercial products earning more than $20 million annually also need prior written authorization, alongside branding and downstream-use requirements.

H3’s public weights are still a substantial release: developers in permitted territories can inspect, modify, and run a capable audio-video Base model, and ComfyUI has already made it far more approachable. The real test is whether MiniMax broadens the license and releases the missing context, 2K regeneration, and sparse-attention components. Otherwise, the most capable version remains tied to its hosted services.