What Is ComfyUI? The Complete Beginner's Guide (2026)

ComfyUI is a free, open-source program for generating AI images, video and audio on your own computer, using a visual editor where you connect "nodes" instead of writing code. Each node does one job (load a model, read a prompt, sample, decode, save), and wiring them together forms a workflow you can save, share and reuse.

Created in January 2023 by the developer known as comfyanonymous and now maintained by Comfy Org, ComfyUI has become the reference tool for advanced Stable Diffusion, SDXL, Flux and AI video users. It is released under the GPL-3.0 license and runs locally on Windows, macOS and Linux.

In this guide, you'll learn how ComfyUI works, what it can generate, how it compares to Automatic1111 and Forge, what hardware it needs, and the honest downsides of running it yourself.

How does ComfyUI work?

ComfyUI works as a node graph: every step of image generation is a box on a canvas, and you draw links between boxes to pass data from one step to the next. When you click Run, ComfyUI executes the graph and only re-runs the nodes whose inputs changed, which makes iterating much faster.

The default text-to-image workflow has six core nodes:

1. Load Checkpoint: loads the model (for example SDXL or Flux) along with its CLIP text encoder and VAE.
2. CLIP Text Encode (positive): turns your prompt into something the model understands.
3. CLIP Text Encode (negative): describes what you don't want in the image.
4. Empty Latent Image: sets the resolution and batch size.
5. KSampler: the actual generation step, where you choose the seed, steps, CFG scale, sampler and scheduler.
6. VAE Decode then Save Image: converts the result from latent space into a viewable image.

What is a ComfyUI workflow?

A ComfyUI workflow is the full graph of connected nodes, saved as a JSON file. ComfyUI also embeds the workflow in the metadata of every PNG it generates, so dragging an image back into the window restores the exact setup that produced it. This is why workflows are so easy to share online.

What are custom nodes?

Custom nodes are community extensions that add new features: face detailing, upscaling, ControlNet, IP-Adapter, video interpolation and more. Over 5,000 custom nodes exist, and the built-in manager installs them in a few clicks. They are ComfyUI's biggest strength, and also its biggest source of breakage.

What can you do with ComfyUI?

ComfyUI supports almost every major open model as soon as it is released, often on day one. That is the main reason power users choose it.

On top of the base models, you can stack LoRAs (small add-on models that teach a style or character), ControlNet (guide the pose or composition), upscalers and face detailers. All of it lives in one graph, which is what makes ComfyUI so flexible.

ComfyUI also exposes a WebSocket API, so developers use it as a generation backend behind apps and websites, not just as a desktop tool.

ComfyUI vs Automatic1111 vs Forge

ComfyUI is more powerful and faster to adopt new models; Automatic1111 and Forge are simpler for basic image generation. The right choice depends on whether you want control or convenience.

Bottom line: pick Automatic1111 or Forge if you just want to type a prompt and get an image. Pick ComfyUI if you want video, the latest models, or complex multi-step pipelines.

ComfyUI system requirements

ComfyUI can technically start on 4 GB of VRAM and 8 GB of RAM, but a comfortable experience needs a recent NVIDIA GPU with 12 GB of VRAM or more. Video models need far more.

You will also want 16–32 GB of system RAM and an SSD with at least 50–100 GB free: a single model checkpoint weighs between 2 and 25 GB, and collections grow fast. NVIDIA cards work best; AMD (ROCm), Intel Arc and Apple Silicon are supported with more caveats. CPU-only mode exists but is impractically slow.

How to install ComfyUI

There are four main ways to install ComfyUI:

1. Comfy Desktop (Windows and macOS): the official installer, which sets up Python and PyTorch for you. The easiest local option.
2. Windows Portable: a 7z archive you extract and run, with everything bundled.
3. Manual install: clone the GitHub repository and install the Python dependencies yourself. Required on Linux and for full control.
4. comfy-cli: a command-line installer and manager.

Comfy Org also offers Comfy Cloud, a hosted version billed by GPU time, with a limited free tier and paid plans starting around $20 per month.

The downsides of running ComfyUI yourself

ComfyUI is excellent, but self-hosting it is a hobby in itself. Before you commit, here is what it really involves:

• Expensive hardware. A GPU that handles SDXL and video comfortably (RTX 3090, 4090 or 5090) costs anywhere from several hundred to over two thousand dollars, plus the electricity.
• Model management. You download checkpoints, LoRAs, VAEs, text encoders and upscalers from different sites, and each must go in the right folder with the right version.
• Broken custom nodes. An update to ComfyUI, PyTorch or a single extension can break a workflow that worked yesterday. Dependency conflicts between custom nodes are the most common complaint in the community.
• The learning curve. Understanding samplers, schedulers, CFG, denoise strength and latent upscaling takes weeks of trial and error.
• Out-of-memory errors. Video generation and high resolutions regularly hit the limits of consumer GPUs.
• Time. Many users spend more hours maintaining their setup than actually creating.

If you enjoy tinkering, that is part of the fun. If you just want results, there is a shortcut.

Skip the hassle: use Yamete.gg

If you want ComfyUI-quality results without installing, updating or debugging anything, use Yamete.gg. Yamete runs optimized ComfyUI workflows on its own dedicated GPU farm, so you get the power of the pipeline without touching a single node.

• No GPU required: generate from any browser, on desktop or mobile.
• Curated models, already tuned: popular styles like Pony and Illustrious are ready to use with the right settings (see our Illustrious vs Pony guide).
• Images and video: the same platform handles both, with no out-of-memory errors.
• Face detailing and upscaling built in: the steps you would chain manually in ComfyUI run automatically.
• No maintenance: model updates and broken nodes are our problem, not yours.

New to prompting? Start with our beginner's guide to AI image generation, then try Yamete.gg for free.

Yamete.gg is an adults-only platform (18+).

ComfyUI FAQ

Is ComfyUI free?

Yes. ComfyUI is free and open source under the GPL-3.0 license. You only pay for your hardware and electricity, or for optional paid API nodes and Comfy Cloud.

Is ComfyUI better than Automatic1111?

For advanced users, yes: ComfyUI supports new models faster, handles video natively and uses VRAM more efficiently. For beginners who just want to type a prompt, Automatic1111 or Forge are easier to learn.

How much VRAM do I need for ComfyUI?

ComfyUI can run on 4 GB of VRAM, but 8–12 GB is the practical minimum for SDXL and 16–24 GB is recommended for AI video models like Wan or LTX-Video.

Can ComfyUI run on a Mac?

Yes. ComfyUI supports Apple Silicon (M1 to M4) through the official desktop app, but generation is noticeably slower than on a comparable NVIDIA GPU.

Can ComfyUI generate videos?

Yes. ComfyUI natively supports video models such as Wan 2.2, LTX-Video and HunyuanVideo, for both text-to-video and image-to-video.

Can I use ComfyUI online without installing it?

Yes. You can use a hosted service such as Comfy Cloud, or a platform like Yamete.gg that runs ComfyUI workflows for you behind a simple interface.