Text / Image to Video — Two Stage
The recommended default for LTX-2.5 in ComfyUI. Stage 1 samples the clip at base resolution from your prompt (and an optional first-frame image). The latent is then upscaled 2× spatially and refined for three more steps, which is where most of the fine texture comes from. Audio is generated in the same pass and muxed into the output.
Required models
Drop each file into the matching folder under ComfyUI/models/, or let Workflow Overview download them all.
| File | Folder | Size | Purpose | Link |
|---|---|---|---|---|
ltx-2.5-22b-distilled-transformer-bf16.safetensors | ComfyUI/models/diffusion_models/ | 42 GB | The LTX-2.5 22B distilled video model — used by every example workflow. Few sampling steps, built for fast iteration. | Hugging Face |
↳ lower-VRAM alternative ltx-2.5-22b-distilled-transformer-comfy-int8-convrot.safetensors | ComfyUI/models/diffusion_models/ | 21.5 GB | INT8 — about half the size; the usual pick for 24 GB cards. | Hugging Face |
↳ lower-VRAM alternative ltx-2.5-22b-distilled-transformer-nvfp4.safetensors | ComfyUI/models/diffusion_models/ | 18.7 GB | NVFP4 — smallest; needs an NVIDIA GPU with FP4 support (Blackwell). | Hugging Face |
gemma4-12b-with-proj-ltx-2.5-bf16.safetensors | ComfyUI/models/text_encoders/ | 26.3 GB | Gemma 4 12B text encoder with the LTX-2.5 projection — turns your prompt into conditioning. Required by all workflows. | Hugging Face |
↳ lower-VRAM alternative gemma4-12b-with-proj-ltx-2.5-comfy-int8-convrot.safetensors | ComfyUI/models/text_encoders/ | 15.4 GB | INT8 text encoder — saves ~11 GB on disk and in memory. | Hugging Face |
ltx-2.5-video-vae-bf16.safetensors | ComfyUI/models/vae/ | 1.5 GB | Video VAE — encodes input frames and decodes the generated latents to pixels. | Hugging Face |
ltx-2.5-video-vae-conv-bf16.safetensors | ComfyUI/models/vae/ | 1.5 GB | Convolutional video VAE variant referenced by the example graphs' decode path. | Hugging Face |
ltx-2.5-audio-vae-bf16.safetensors | ComfyUI/models/vae/ | 0.4 GB | Audio VAE — decodes the synchronized soundtrack LTX-2.5 generates alongside the video. | Hugging Face |
ltx-2.5-latent-spatial-upscaler-x2-bf16-1.0.safetensors | ComfyUI/models/latent_upscale_models/ | 1 GB | 2× latent spatial upscaler — the second stage of every two-stage workflow. | Hugging Face |
How to use
- 1
Open ComfyUI (current version, with ComfyUI-LTXVideo installed via Manager).
- 2
Workflow → Open and pick the downloaded .json, or drag the file onto the canvas.
- 3
Open Workflow Overview → Missing Models → Download all, and wait for the files to finish.
- 4
Type your prompt in the Inputs panel. Describe subject, motion, camera and lighting in one scene.
- 5
Optional: load a still image as the first frame for image-to-video.
- 6
Set duration (frame count must be 1 + a multiple of 8; the graph converts fps × seconds for you).
- 7
Click Run. Stage 1, upscale and refine execute in sequence; the output node shows the final video with audio.
VRAM
Which transformer build fits your card for this graph.
| VRAM | Example cards | Verdict | Transformer | Advice |
|---|---|---|---|---|
| 24 GB | RTX 3090, 4090, A5000 | OK | int8 | Workable with the INT8 transformer + INT8 text encoder and the low-VRAM loader nodes. Two-stage graphs run; keep decode tiles small. Leave bf16 files for 32 GB+ cards. |
| 32 GB | RTX 5090, V100 32G | Comfortable | bf16 | Lightricks' stated minimum. bf16 transformer with the low-VRAM loaders fits; INT8 text encoder frees headroom for larger decode tiles and longer clips. |
| 48 GB+ | RTX 6000 Ada, A6000, H100 | Comfortable | bf16 | Everything in bf16 without offloading. Increase the decode tile size (see the Decode notes in each graph) for faster runs. |
Official requirement is 32 GB+. Lower tiers are guidance for quantized builds.
Under 24 GB?
The same LTX-2 model runs in our browser generator — 4K with audio, no setup, free credits to start.
Troubleshooting
FAQ
Other workflows
Text / Image to Video — Single Stage
Same inputs, one distilled pass, no upscaler. Faster and lighter; less spatial detail than two-stage.
Audio to Video — Two Stage
Generate video that follows an input soundtrack. The original waveform is kept and muxed into the output.
Text to Audio — Single Stage
Audio only. No video VAE, no upscaler — the lightest graph in the set.