Sulphur 2: A 9B Video Generation Model Based on LTX 2.3
Sulphur 2 is a community fine-tune of LTX 2.3 offering text-to-video and image-to-video generation with a built-in prompt enhancer and distill LoRA, trained on 125K+ curated clips.
Overview
Released by SulphurAI on May 3, 2026, Sulphur 2 is a community video generation model fine-tuned on 125K+ curated video clips. Built on top of Lightricks' LTX 2.3 architecture (a 22B parameter diffusion transformer), it provides both text-to-video and image-to-video generation.
The model supports all LTX 2.3 native formats and comes with several companion components including a prompt enhancer, a distill LoRA for faster inference, and ready-to-use ComfyUI workflows.
Key Features
| Feature | Description |
|---|---|
| Architecture | Fine-tuned from Lightricks LTX 2.3 (22B DiT) |
| Task Support | Text-to-Video (T2V) and Image-to-Video (I2V) |
| Model Size | ~9B effective parameters (dev BF16: 16.7 GB, FP8: 8.5 GB) |
| Prompt Enhancer | Bundled GGUF prompt enhancer available |
| Distill LoRA | 1.1 distilled LoRA for faster generation |
| Training Data | 125K+ curated video clips |
| License | Custom non-commercial / research |
Model Variants
Sulphur 2 ships with several weight variants to accommodate different hardware:
- sulphur_dev_bf16.safetensors (~16.7 GB): Full precision dev version
- sulphur_dev_fp8mixed.safetensors (~8.5 GB): Quantized dev version for lower VRAM
- sulphur_distil_bf16.safetensors: Distilled version for faster inference
- sulphur_lora_rank_768.safetensors: LoRA for fine-tuning
- distill_loras/ltx-2.3-22b-distilled-lora-1.1.safetensors: Additional distill LoRA
Prompt Enhancer
One of the standout features of Sulphur 2 is the inclusion of a dedicated prompt enhancer: a small language model packaged as GGUF that automatically rewrites and enriches user prompts for better video generation results. Two variants are available:
- Standard prompt enhancer: General-purpose prompt rewriting
- Alt prompt enhancer: An alternative variant without prompt filtering
The prompt enhancer can be loaded in LM Studio or any GGUF-compatible inference UI.
ComfyUI Integration
Sulphur 2 ships with ready-to-use ComfyUI workflows included in the model repository:
| Workflow | Description |
|---|---|
| T2V Base | Text-to-video base workflow |
| T2V Distilled | Text-to-video with distill LoRA |
| I2V Base | Image-to-video base workflow |
| I2V Distilled | Image-to-video with distill LoRA |
Simply download the model weights from Hugging Face and place them in your ComfyUI/models/diffusion_models/ directory, then load one of these workflows and select the Sulphur 2 checkpoint.
Performance & Quality
Sulphur 2 was trained on a carefully curated dataset of 125K+ video clips focused on human-centric and diverse visual content. It handles:
- Human motion and interaction with improved consistency
- Improved prompt adherence compared to the base LTX 2.3 for certain creative use cases
- Native portrait and character-focused generation
Availability
- Hugging Face: SulphurAI/Sulphur-2-base
- CivitAI: Sulphur 2 Base
- Browser Demo: sulphur2ai.com
- Discord: Join community
Summary
Sulphur 2 represents one of the most popular community fine-tunes of LTX 2.3, offering creators an alternative for video generation with helpful tooling like prompt enhancement and distilled inference. Its combination of quality, flexibility, and ready-to-use ComfyUI workflows makes it a compelling option for video generation enthusiasts.