MiniMax H3¶

Development line: project:minimax-h3 · thread minimax-h3
Last event: 2026-07-31 · 1 dated since 2026-07-31 · Researched: 2026-09-04 · confidence: high

What it is¶

MiniMax H3 is a 33B open-weight audiovisual video base model for creators and developers choosing local 768p generation or an API-backed 2K workflow.

• Inputs: text, first/last frames, or image, video, and audio references.
• Output: synchronized video with native stereo audio; FL2VA covers text/keyframe work and Ref2VA covers multimodal reference work.
• Limit: 4–15 seconds; Context-IR and H3-Regenerate-2K remain hosted in the official full-2K workflow.

Development line¶

• 2026-07-31 — MiniMax publishes an official MiniMax H3 blog entry. MiniMax launched H3 with multimodal context and native-stereo video up to 2K/15 seconds; weights were promised for a later release.

What changed¶

• 2026-07-31: MiniMax launched H3 with multimodal context and native-stereo video up to 2K/15 seconds; weights were promised for a later release.
• 2026-08-03: MiniMax opened H3 Base weights, with FL2VA and Ref2VA checkpoints while Context-IR and 2K regeneration stayed in the hosted pipeline.
• 2026-08-10: A linked AMA clarified prompt/workflow guidance and future local-release plans; it was not a new versioned model release.
• 2026-08-27: fal released H3 Max, a post-trained MiniMax H3 derivative offered through fal.

How to use this¶

From 2026-07-31, start with the official MiniMax H3 page to evaluate the project. Do not infer features or deployment readiness from early materials alone.

1. For the hosted path, create an API key and POST an application/json request with Bearer authentication to the H3 video-generation endpoint. — https://platform.minimax.io/docs/api-reference/video-generation-v2-create
2. Choose MiniMax-H3, include one non-empty text item, then add either first/last frames or reference image, video, and audio inputs; the two input modes cannot be mixed in one request. — https://platform.minimax.io/docs/api-reference/video-generation-v2-create
3. Set H3 resolution to 768P or 2K and duration from 4 to 15 seconds, then poll the task or register a callback for queued, running, succeeded, failed, or cancelled states. — https://platform.minimax.io/docs/api-reference/video-generation-v2-create
4. For local 768p, download FL2VA for text/first-last-frame work or Ref2VA for multimodal reference work, then serve the matching H3-Base checkpoint with a supported framework. — https://www.minimax.io/news/minimax-h3-open-source
5. For a hosted post-trained derivative instead of the open Base, use fal's H3 Max through its Playground or API. — https://blog.fal.ai/introducing-h3-max-by-fal/

Best practices¶

• Use Context-IR as a planning/preprocessing stage, or reproduce its structure from the provider prompt guidance, before sending work to H3 Base. — https://www.minimax.io/news/minimax-h3-open-source
• For first/last-frame work, follow the Base guide's frame-alignment instruction and describe a continuous path to the final frame; keep later shot cut times strictly increasing. — https://huggingface.co/MiniMaxAI/MiniMax-H3/blob/main/docs/VIDEO_PROMPT_WRITING_GUIDE_base_en.md
• For full reference, define each Subject, Picture, Video, and Audio label once and preserve its meaning; state whether audio is copied or only referenced. — https://huggingface.co/MiniMaxAI/MiniMax-H3/blob/main/docs/VIDEO_PROMPT_WRITING_GUIDE_ref_en.md
• Treat local H3 Base output as 768p; use the declared full 2K workflow instead of assuming Context-IR or H3-Regenerate-2K ships with the weights. — https://www.minimax.io/news/minimax-h3-open-source
• Review the Community License before commercial or hosted deployment: it excludes several territories and requires separate authorization above US$20 million annual revenue. — https://huggingface.co/MiniMaxAI/MiniMax-H3/blob/main/LICENSE

Superseded by this¶

• 2026-08-03: the 2026-07-31 state in which MiniMax H3 weights were only planned for release in the coming days.

Still unknown¶

• Whether MiniMax-H3-Max on the MiniMax API and H3 Max on fal share the same checkpoint.
• Whether MiniMax released H3-Context-IR, H3-Regenerate-2K, or their sparse-attention implementation for local use.
• Minimum GPU or VRAM requirements for local serving; the SGLang command is an example with four GPUs, not a minimum specification.

Sources¶

Agent brief¶

• Subject: project:minimax-h3, thread minimax-h3, 1 dated events 2026-07-31 → 2026-07-31.
• Practical note: From 2026-07-31, start with the official MiniMax H3 page to evaluate the project. Do not infer features or deployment readiness from early materials alone.
• Confidence: high. Dated supersedes above are the authority for what is obsolete.

2026-09-05 — MiniMax H3 Semantic Bridge adds an adapter for H3's FL2VA text path¶

MiniMax H3 Semantic Bridge is a ComfyUI conditioning adapter for the standard MiniMax H3 FL2VA text-conditioned workflow. It is a community project, not an official MiniMax or SenseNova release. Ref2VA support was not released because author tests degraded singing and lip-sync.

Usage and practices¶

• Install the released custom-node archive under ComfyUI/custom_nodes/. Place MiniMaxH3_SemanticBridge_v1.safetensors under ComfyUI/models/semantic_bridge/, restart ComfyUI, and start from the supplied workflow reference. Source
• Use v1 only with the standard MiniMax H3 FL2VA/text-conditioned route. Do not put it into Ref2VA or another reference-conditioned workflow. Source
• Begin at alpha 0.10 with per-token magnitude matching. Compare native H3 and bridge-enabled output using the same prompt, seed, and generation settings. Treat the published alpha 0.15 comparisons as examples rather than a universal preset. Source
• Keep the author's representation-space cosine measurements separate from video-quality claims. The release says they measure agreement with a teacher-derived representation, not perceptual quality or universal prompt-adherence improvement. Source

Additional evidence¶

• 2026-09-05: The public repository is speach1sdef178/MiniMax-H3-Semantic-Bridge at revision 8c2d9b0edb844d6002864a9addd61458dbe81c22. Public files include the v1 adapter, custom-node archive, workflow examples, checksums, README, research material, NOTICE, and licenses. This is a community project, not an official MiniMax or SenseNova release. Source
• 2026-09-05: The author reports that v1 belongs only on the standard MiniMax H3 FL2VA/text-conditioned route. Ref2VA/reference-audio experiments degraded singing and lip-sync, so no Ref2VA node was released. Alpha 0.10 is the author's starting point. The alpha 0.15 A/B examples are qualitative illustrations, not proof of general gains. Source

Limits and open questions¶

• No independent reproduction, standardized human-preference benchmark, or separate third-party performance validation was found for this exact adapter as of 2026-09-05.
• The 5-6M parameter count, representation metrics, training split, and compatibility claims are author-published release claims, not independently audited here.
• Chinese queries found no exact zh-CN announcement, tutorial, or independent reproduction for MiniMax H3 Semantic Bridge. The examined MiniMaxH3 CondBridge Qwen3.5-4B result is a different project and must not be merged into this event.
• We did not download or run the package. Runtime compatibility, artifact integrity beyond the named revision, license interpretation, and practical video gains remain unverified.