Sulphur 2 — Open AI Video Model
That Actually Listens to You
Sulphur 2 is an open-weights AI video generation model fine-tuned on LTX 2.3 and 125,000+ real-world clips — delivering cinematic text-to-video and image-to-video with fewer creative restrictions than any commercial alternative.
What Is Sulphur 2 and Why Does It Matter?
Sulphur 2 is a community-distributed, open-weights video generation model fine-tuned from Lightricks' LTX 2.3 architecture — a DiT-based (Diffusion Transformer) foundation built for text-to-video and image-to-video generation. The Sulphur 2 base model was trained on roughly 125,000 curated video clips to target the most common open-source artifacts: jitter, anatomical breakage, and frame-to-frame inconsistency.
Unlike closed platforms that lock you into their infrastructure and content policies, Sulphur 2 (SulphurAI/Sulphur-2-base) publishes weights on Hugging Face for local use — and functions as a verified drop-in replacement for LTX 2.3 in any existing ComfyUI workflow, no rebuild required.
Smoother Motion Than Base LTX 2.3
The fine-tuning pass specifically targeted limb deformation and frame jitter. Community testing confirms measurably cleaner human motion, steadier camera tracking, and stronger subject consistency over vanilla LTX 2.3 — on the same hardware.
Prompt-Responsive Without Platform Gatekeeping
Sulphur 2 accepts a broader range of legally permissible prompts that commercial platforms routinely block — medical content, realistic storytelling violence, niche artistic styles — while keeping baseline filters for illegal material.
Weights, Workflows, and Prompt Enhancer — All Included
The release includes BF16 and FP8 safetensors, a Distil LoRA, four ComfyUI workflow JSONs, and a Qwen 3.5 9B local prompt enhancer — everything from download to first generation, no hunting for missing pieces.
Everything Sulphur 2 Can Generate
Four production-ready modes, each inherited from LTX 2.3 and refined by fine-tuning on 125k real-world clips.
Text-to-Video — Prompt-Driven Cinematic Generation
Describe your shot in plain language and Sulphur 2 renders a temporally stable clip with consistent subject motion, lighting, and camera behavior across every frame. Fine-tuned on 125k clips specifically to eliminate the limb deformation and jitter that plague base LTX 2.3.
Image-to-Video — Animate Any Still with Precision Control
Upload a reference image as the starting frame and describe the motion you want. Sulphur 2 preserves your subject's identity, color, and composition while adding controlled camera movement — dolly, orbit, push-in. First-frame and last-frame anchoring both supported.
Three Model Tiers for Every Hardware Setup
The release ships three variants to match your GPU: BF16 (46 GB, best quality, 24–32 GB VRAM), FP8 Mixed (29 GB, balanced, 16 GB VRAM), and GGUF Distilled (quantized, fastest, lower spec). Switch between quality and speed without changing your workflow.
Drop-In ComfyUI Replacement for LTX 2.3
Four official JSON workflows — T2V base, T2V distilled, I2V base, I2V distilled — load directly into any existing LTX Video ComfyUI setup. Sulphur 2 is architecture-identical to LTX 2.3, so no node rebuilds, no custom extensions, no reconfiguration required.
Uncensored Training — Fewer Refusals, Same Legal Limits
Commercial platforms block large categories of legal content to manage brand risk. Sulphur 2's training data was filtered only to remove illegal material and 2D animation — everything else, including medical realism, cinematic violence, and mature artistic styles, renders without refusal. Illegal content remains blocked.
Built-In Prompt Enhancer — Qwen 3.5 9B Local LLM
A Qwen 3.5 9B model ships as a GGUF alongside the video weights, runnable in LM Studio. It rewrites vague descriptions into structured, cinematically-worded shot briefs before they hit the video model — measurably improving motion quality and prompt adherence without any prompt engineering knowledge on your end.
See What Sulphur 2 Generates
Community clips generated with Sulphur 2 — text-to-video and image-to-video, running locally via ComfyUI or through the online generator.
"Luxury ceramic coffee cup on dark slate, steam rising, soft studio backlight, warm rim glow, slow dolly-in, macro lens, premium commercial style"
"Filmmaker under neon city lights at night, rain on pavement, slow push-in camera, moody blue and magenta, shallow DOF, film grain"
"Mountain lake at sunrise, mist rolling, birds drifting, slow aerial tracking shot, warm golden light, photorealistic atmosphere"
"Slow orbit camera, light sweeping surface left to right, subtle reflection shift, maintain original composition, premium commercial pacing"
"Subtle orbit motion, natural hair movement in light breeze, golden hour lighting shift, preserve face identity, shallow depth of field"
"Fashion model in modern gallery, smooth handheld camera, white walls, editorial style, confident mood, vertical social format"
Sulphur 2 vs. LTX 2.3, Runway, and Sora
How Sulphur 2 stacks up on the dimensions that matter most to working creators and AI filmmakers.
| Dimension | Sulphur 2 | LTX 2.3 (base) | Runway Gen-4 | Sora |
|---|---|---|---|---|
| Price | Credit plans from $0 | Open weights (hardware only) | $15–$95 / mo | $20+ / mo |
| Open Weights | ✓ | ✓ | ✗ | ✗ |
| Text-to-Video | ✓ | ✓ | ✓ | ✓ |
| Image-to-Video | ✓ | ✓ | ✓ | ✗ |
| First & Last Frame Control | ✓ | ✓ | Partial | ✗ |
| Local / Offline Use | ✓ | ✓ | ✗ | ✗ |
| Official ComfyUI Workflows | ✓ (4 JSONs) | ✓ | ✗ | ✗ |
| Motion Fine-Tune (125k clips) | ✓ Sulphur-specific | Base training only | Proprietary | Proprietary |
| Content Restrictions | Minimal (legal content only) | Moderate | Conservative | Conservative |
| Built-In Prompt Enhancer | ✓ Qwen 3.5 9B | ✗ | Cloud only | Cloud only |
What Creators Are Building with Sulphur 2
From product ads to documentary sequences — real workflows, real outputs, all generated online without a GPU.
Product & Brand Advertising
Animate product shots with cinematic camera moves — orbits, dollies, light sweeps. Sulphur 2 preserves product identity and lighting throughout, giving marketing teams broadcast-quality footage in minutes instead of days.
Narrative & Short Film Storyboarding
Turn script scenes into visual previews before you shoot. Sulphur 2's uncensored training means dramatic, morally complex scenes that commercial tools reject actually render — critical for previsualization work on mature content.
Social & Short-Form Video Content
Generate eye-catching clips for Instagram Reels, TikTok, and YouTube Shorts natively in 9:16 vertical format. Fast turnaround and high motion quality make Sulphur 2 a reliable source for scroll-stopping content at scale.
Medical & Scientific Visualization
Create anatomical explainer sequences, surgical procedure previews, and biological process animations that mainstream platforms routinely block. Sulphur 2's content policy accepts medical realism that education and research projects actually need.
Historical & Documentary Reconstruction
Reconstruct historical events, architecture, and environments from written descriptions or reference photos. Sulphur 2 renders realistic period-accurate scenes without the content refusals that make documentary AI work frustrating on other platforms.
Game & Concept Art Animation
Breathe motion into concept art, character designs, and environment sketches using image-to-video. Upload your artwork, describe the camera move or atmospheric effect, and Sulphur 2 animates it while keeping your original design intact.
Sulphur 2 — Common Questions Answered
Ready to See What Sulphur 2 Can Do?
Generate your first cinematic AI video in the browser — or follow the setup guide to run the open-weights model locally on your own GPU.