ComfyUI MiniMax H3 Extender
A ComfyUI custom node for MiniMax H3 designed to generate long, continuous video sequences from multiple clips while preserving motion, visual continuity, and audio continuity between generations.
The node combines Ref2VA conditioning, Motion Context, disk caching, multi-clip generation, image references, audio references, and final video/audio decoding into a much simpler workflow.
🆕 Per-Clip Local References
Ref2VA clips can now use their own local Picture, Video and Audio references in addition to the existing global references.
Each clip gets a compact Refs panel where local references can be added, removed and previewed without cluttering the main card UI.
Local references use the normal H3 slot numbering and share the same limits as global references:
- up to 9 Pictures
- up to 3 Videos
- up to 3 Audio references
Global references remain global exactly as before. Local references simply use the next available slots for that clip.
If a slot is already used locally, the matching global slot is automatically reserved to avoid conflicts. References coming from a Ref Pack are also handled safely without remapping or blocking generation.
Local Pictures can be edited with the same image editor as global references, and local Video/Audio references include compact preview players directly inside the Refs panel.
All local references are fully included in Project Save/Load, so they are restored automatically with the project.
🆕 Full Batch: Interrupt, Save & Resume
Full Batch workflows are now much safer and easier to manage.
You can interrupt a long Full Batch, keep the clips that are already computed, save the project, close ComfyUI, reload it later, and resume from where you stopped without losing completed work.
This also works with project Save/Load, so long generations can now be split across multiple sessions instead of needing to finish in one run.
Available for both Ref2VA and FL2VA.
🆕 News — Dynamic FL2VA Guides & Native VIDEO Output
🎯 Dynamic Image Guides for FL2VA
FL2VA clips can now use up to 3 independent image guides, each placed at an exact frame_idx.
This is based on ComfyUI's native MiniMaxH3AddGuide support introduced in PR #15439.
You can now build a real visual timeline inside a single generation:
First → Guide 1 → Guide 2 → Guide 3 → Last
MiniMax H3 automatically generates the transitions between these visual anchors, opening the door to controlled transformations, pose changes, camera evolution, action staging and much more.
🎬 Native VIDEO Output
The Final Decode / Preview node now exposes a native ComfyUI VIDEO output.
This makes it possible to connect the final result directly to compatible video nodes such as upscalers, post-processing pipelines and video encoders, without having to reload the generated MP4 manually.
🚀 MiniMax H3 Extender 2.0.0
Version 2.0.0 is now available!
This release introduces FL2VA support
It also includes major speed and memory optimizations, with reduced RAM/VRAM usage, faster continuity handling, smoother preview behavior, and improved performance on longer projects.
Project save/load, preview restoration, clip continuity, and overall stability have also been improved.
MiniMax H3 Extender 2.0.0 is now the new base for the project.
Thanks to everyone testing, reporting issues, and helping improve the extension ❤️
🎛️ New — Per-Clip LoRAs
Each clip card can now use its own LoRA.
- choose a LoRA directly inside the clip card
- set its strength per clip
- add multiple LoRAs to the same clip
- LoRA rows grow automatically as needed
- remove a LoRA and the list compacts automatically
- clips without LoRAs continue to use the incoming model unchanged
- global LoRAs applied before the Extender still work as before
- per-clip LoRA choices are saved with the project
This makes it possible to change style, motion or behavior from one clip to another while keeping the Extender’s normal continuity workflow.
🎬 New — Video & Audio References for MiniMax H3
The Extender now supports MiniMax H3 video references directly inside the workflow.
You can now use external video frames as <Video N> references, combine them with image references, and optionally attach the matching video audio for motion, timing, camera behavior and lip-sync guidance.
What’s new
- up to 3 video references
- up to 3 matching video-audio references
- up to 3 standalone audio references
<Video 1>, <Video 2>, <Video 3> support in prompts- stable logical video slots with no automatic remapping
- dynamic AV inputs in the node UI
- optional paired
ref_video_audio_N inputs
- long standalone audio references are automatically sliced along the clip timeline
- video soundtracks are cropped to the effective reference-video duration
- reference-video inputs are automatically aligned to H3’s required
17k+5 frame structure
- external Prompt Pack and Reference Pack sockets remain at the bottom of the node
Automatic FPS correction
MiniMax H3 expects reference-video frames at 24 fps, but real source videos can be 23.976, 25, 30, 45, 50, 60 fps, etc.
The Extender now accepts the original source FPS through:
ref_video_fps_1ref_video_fps_2ref_video_fps_3
The reference-video frame batch is then automatically resampled to 24 fps while preserving the original duration before it is sent to H3.
This fixes cases where the end of a reference video appeared to be missing because a non-24-fps image batch was previously interpreted as if it were already 24 fps.
Typical workflow:
Load Video
↓
Get Video Components
├── images → ref_video_1
├── fps → ref_video_fps_1
└── audio → ref_video_audio_1
Character replacement
Video references can be combined with image references for workflows such as:
- character replacement
- motion transfer
- pose and body-performance transfer
- camera-motion transfer
- timing preservation
- lip-sync guidance from the original video audio
For example:
<Picture 1> defines the new character identity<Video 1> provides the original performance, timing and camera behaviorref_video_audio_1 provides the matching audio reference
This keeps the Extender’s existing internal image-reference system fully intact while adding proper H3 Ref2VA video/audio support.
Added support for an external prompt pack through the new MiniMax H3 Prompt Pack Bridge node.
Reference Pack Bridge
A new node MiniMax H3 Reference Pack Bridge has been added.
This allows external ComfyUI IMAGE outputs to be injected directly into the Extender’s existing internal reference slots, while keeping the current internal reference system fully intact.
You can now mix both approaches in the same workflow:
- internal references loaded with the Extender
- external references coming from
Load Image, crop/resize nodes, video frames, Kontext-style preprocessing, or any other IMAGE source
- each external input maps directly to its matching
<Picture N> slot
- empty external slots leave the existing internal reference untouched
- reference indices are never compacted or remapped
- once imported, the external image becomes a normal internal reference with thumbnail, project persistence and Save/Load compatibility
- disconnecting the external input does not remove the imported internal reference
- unchanged external images are not rewritten on every run
The Bridge is optional and does not replace the current reference workflow. It simply adds a flexible external entry point for advanced ComfyUI pipelines.
🎬 Save Preview
The Final Decode / Preview node now includes a dedicated Save Preview button.
It saves the currently assembled Extender preview exactly as shown, including:
- seam handling
- assembled audio
- per-clip color corrections
- ComfyUI workflow metadata
- ComfyUI prompt metadata
The saved MP4 can be dragged back into ComfyUI to restore the workflow.
🎨 Real-Time Per-Clip Color Editor
Each generated clip now has its own color editor, accessible directly from the clip card with the 🎨 button.
You can adjust:
- Saturation
- Contrast
- Brightness
The editor provides a live looping preview around the selected clip, including a short part of the previous and next clips, making it much easier to visually match colors between continuations.
Corrections are:
- stored independently for every clip
- editable again at any time
- non-destructive
- preserved in
.ext Save/Load projects
- automatically included in Preview, Full Batch and Save Preview
Color correction is applied only to the decoded video and does not modify Motion Context, latent data or clip validation.
A small ✓ next to the palette indicates that a clip has an active color correction.
⚡ Full Batch Integration
Full Batch correctly preserves and applies all previously configured clip corrections during final assembly.
You can therefore:
- Generate several clips
- Color-correct individual clips
- Continue generating additional clips
- Run Full Batch
- Obtain the complete sequence with all previous adjustments preserved
💾 Save / Load Project
Per-clip color adjustments are stored inside .ext projects.
Loading a project restores the clip settings and color correction state, allowing you to continue exactly where you stopped.
https://github.com/user-attachments/assets/a18cc6a5-2340-474e-9d3b-b784cd41584a
Keeping References Consistent Across Clips
When using image references, it is strongly recommended to place a subject_definitions block at the beginning of every clip prompt.
This helps MiniMax H3 keep the same subjects, identities, clothing, visual roles and even the environment associated with a reference image from one clip to the next.
Example
subject_definitions:
<Picture 1> is the reference image defining the exact visual appearance, identity, face, hairstyle, body proportions, clothing, accessories, and overall look of <Subject 1>, as well as the established environment and visual context of the scene.
<Picture 2> is the reference image defining the exact visual appearance, identity, face, hairstyle, body proportions, clothing, accessories, and overall look of <Subject 2>.
<Subject 1> is the exact same woman shown in <Picture 1>.
<Subject 2> is her friend, the exact same woman shown in <Picture 2>.
<Subject 3> is the same street environment and scene context established in <Picture 1>.
Place this subject_definitions block at the very beginning of every clip prompt.
The important point is that a reference image does not have to represent only a character.
A reference can also define the environment, location or visual context of the sequence.
In the example above:
<Picture 1> defines the appearance of <Subject 1><Picture 2> defines the appearance of <Subject 2><Picture 1> also defines the street environment used as <Subject 3>
So the same reference image can be used both to preserve a character and to preserve the environment established by that image.
Repeating these definitions at the beginning of each clip prompt helps MiniMax H3 maintain the intended reference roles throughout the entire sequence.
Features
- Multi-clip MiniMax H3 generation
- Continuous Motion Context between clips
- Video and audio latent continuity
- Disk-based latent cache
- Clip-by-clip generation workflow
- Full batch generation mode
- Per-clip prompt
- Per-clip seed
- Seed modes:
- Randomize
- Fixed
- Increment
- Decrement
- Per-clip duration
- Clip validation system
- Dynamic image reference inputs
- Up to 9 image references
- Optional audio reference
- Shared references automatically applied to all clips
- Native MiniMax H3 Ref2VA conditioning
- Native ComfyUI sampling progress
- Final video preview
- Final video + audio export
- Seam correction between generated clips
- Audio seam correction / declick
- H.264, H.265 / HEVC and FFV1 export
- Persistent disk cache allowing generation to be resumed
Clip Validation
Each clip has a Validated checkbox.
The validation system allows you to progressively build a long sequence without regenerating clips that have already been accepted.
When a clip is validated:
- its generated latent remains stored in the disk cache;
- the clip is locked and reused directly;
- it becomes the Motion Context source for the next clip;
- it will not be sampled again while it remains valid.
A typical workflow is:
Clip 1 → Generate
Clip 1 → Validate
Clip 2 → Generate
Clip 2 → Retry if needed
Clip 2 → Validate
Clip 3 → Generate
Clip 3 → Retry if needed
Clip 3 → Validate
This makes it possible to build a sequence one clip at a time while preserving all previously accepted generations.
Validation always forms a continuous chain from the beginning of the sequence.
For example:
Clip 1 ✅
Clip 2 ✅
Clip 3 ⬜
Clip 4 ⬜
If an earlier clip is unvalidated, every clip after it is automatically unvalidated as well, because each continuation depends on the previous generated clip.
Changing a generation parameter also invalidates the sequence when necessary. This includes changes to:
- prompt
- seed
- duration
- model
- sampling settings
- image references
- audio reference
- Motion Context settings
The affected clip and all dependent clips after it must then be regenerated.
In clip_by_clip mode, the Extender works on the first unvalidated clip in the sequence.
The intended workflow is therefore:
Generate → Preview → Retry if needed → Validate → Continue
This allows long MiniMax H3 sequences to be created progressively without repeatedly regenerating clips that are already approved.
Installation
ComfyUI Manager
Search for:
MiniMax H3 Extender
and install it directly from ComfyUI Manager.
Manual Installation
Open a terminal in:
ComfyUI/custom_nodes/
Then run:
git clone https://github.com/tritant/ComfyUI_MiniMax_H3_Extender.git
Restart ComfyUI after installation.
ℹ️ About the old Disk Join nodes
The old low-level Motion Context Disk Join workflow is now considered deprecated and is no longer actively maintained.
New workflows should use the main MiniMax H3 Extender node, which now handles cache management, references, trimming, validation, preview, seam correction, project Save/Load, color correction and final assembly internally.
Thanks again to everyone testing the node and reporting edge cases.
The Extender is becoming much more comfortable to use for long H3 sequences.
It's a ComfyUI custom node for the MiniMax H3 video model: it chains multiple generated clips into one long sequence while preserving motion, visual and audio continuity across clip boundaries.