ComfyUI is an open-source, node-based program that allows users to generate images from a series of text prompts. It uses free diffusion models such as Stable Diffusion as the base model for its image capabilities, combined with other tools such as ControlNet and LCM Low-rank adaptation, with each tool being represented by a node in the program. The software is designed to provide a flexible, visual interface for constructing complex image generation pipelines, and it has become one of the most popular user interfaces for Stable Diffusion, alongside Automatic1111.
ComfyUI was released on GitHub in January 2023. According to comfyanonymous, the creator, a major goal of the project was to improve on existing software designs in terms of the user interface. The creator had been involved with Stability AI, but by 3 June 2024 that involvement had ended, and an organization called Comfy Org had been created along with the core developers. In July 2024, NVIDIA announced support for ComfyUI within its RTX Remix modding software. In August 2024, support was added for the FLUX diffusion model developed by Black Forest Labs, and Comfy Org joined the Open Model Initiative created by the Linux Foundation. As of July 2026, the project has 122k stars on GitHub.
Features
ComfyUI's main feature is that it is node based. Each node has a function such as "Model loader" or "CLIP Text Encode". The nodes are connected to form a control-flow graph called a workflow. When a prompt is queued, a highlighted frame appears around the currently executing node, starting from "load checkpoint" and ending with the final image and its save location. Workflows commonly consist of tens of nodes, forming a complex directed acyclic graph. Node types include loading a model, specifying prompts, samplers, schedulers, VAE decoders, face restoration and upscaling models, LoRAs, embeddings, and ControlNets.
Several samplers are supported, such as Euler, Euler_a, dpmpp_2m_sde, and dpmpp_3m_sde. Workflows can be saved to a file, allowing users to re-use node workflows and share them with other users. The file format for the workflows is in JSON and can be embedded in the generated images. Users have also created custom extensions to the base system which are exposed as new nodes, such as the extension for AnimateDiff, which aims to create videos. ComfyUI has been described as more complex compared to other diffusion UIs such as Automatic1111. A default node group is also included with the program.
As of December 2024, 1,674 nodes were supported. ComfyUI supports multiple text-to-image models including Stable Diffusion, Flux, and Tencent's Hunyuan-DiT, as well as custom models from Civitai like Pony.
Role in AI Image Generation
ComfyUI occupies a significant position in the Generative AI ecosystem as a tool for building and running diffusion models. Unlike simpler interfaces that abstract away the underlying pipeline, ComfyUI exposes the full process as a visual graph, giving users granular control over each step from model loading to final output. This makes it particularly valuable for researchers, developers, and advanced users who need to experiment with different model configurations, samplers, and auxiliary tools like ControlNet or LoRAs.
The node-based architecture aligns with the broader trend in Machine learning toward modular and reusable components. By representing each operation as a node, ComfyUI enables the rapid prototyping of new workflows without writing code, which has contributed to its adoption in both academic and hobbyist communities. Its support for a wide range of models, including those from Black Forest Labs and tencent, further cements its role as a versatile platform for AI-driven creativity.
Security Incident: LLMVision Extension Compromise
In June 2024, a hacker group called "Nullbulge" compromised an extension of ComfyUI to add malicious code to it. The compromised extension, called ComfyUI_LLMVISION, was used for integrating the interface with AI language models GPT-4 and Claude 3, and was hosted on GitHub. Nullbulge hosted a list of hundreds of ComfyUI users' login details across multiple services on its website, while users of the extension reported receiving numerous login notifications. vpnMentor conducted security research on the extension and claimed it could "steal crypto wallets, screenshot the user's screen, expose device information and IP addresses, and steal files that contain certain keywords or extensions".
Nullbulge's website claims they targeted users who committed "one of our sins", which included AI-art generation, art theft, promoting cryptocurrency, and any other kind of theft from artists such as from Patreon. They claimed that they were "a collective of individuals who believe in the importance of protecting artists' rights and ensuring fair compensation for their work" and that they believed that "AI-generated artwork is detrimental to the creative industry and should be discouraged".
Impact and Community
ComfyUI's open-source nature and active development have fostered a large community of users and contributors. The project's GitHub repository serves as a hub for sharing workflows, custom nodes, and extensions, which has accelerated the spread of new techniques and models. The integration with platforms like Civitai allows users to easily import custom models, further expanding the tool's capabilities.
The software's popularity is reflected in its high star count on GitHub, indicating strong community interest and approval. Its role in the broader AI landscape is notable because it democratizes access to advanced image generation techniques, enabling individuals and small teams to leverage state-of-the-art models without needing extensive programming expertise. As of 2026, ComfyUI continues to evolve, with ongoing support for new models and features, maintaining its status as a key tool in the AI art and research communities.