Open-source AI image generators and editors

The open-source image tools are where people who want control end up. Hosted image generators are quicker to start with; these let you choose the model, run it on your own GPU, keep your images private and build repeatable pipelines. The list covers the interfaces people run models in, the tools that edit and repair images, and the skills that help an agent write better image prompts.

Interfaces, pipelines and helpers

Web interfaces for Stable Diffusion and FLUX are the usual starting point: a prompt box, settings, and a gallery. Node-based editors trade that simplicity for pipelines you can save and rerun, which is what you want for consistent product shots or a series in one style.

Helper tools fix one thing well: upscaling, inpainting a region, removing a background. Many plug into the bigger interfaces.

Prompt libraries and image skills work on the other side. They help an agent write a prompt that gets the style you want, which cuts the number of attempts before you have a usable image.

Before you install

Check the hardware. Most local image models want a graphics card with plenty of memory; a few entries run on a CPU, slowly. If you do not have the hardware, a hosted service will be faster and cheaper than buying it.

Check the model licence as well as the tool licence. The interface may be MIT while the model you load into it has its own rules for commercial use.

The list

From SkillScout's catalogue, counted on 27 October 2026: 25 entries matched this topic, and these are the 12 with the most GitHub stars, one per project, after a review for false matches. Descriptions are each project's own. Stars show popularity, not fit.

  1. stable-diffusion-webui

    Open-source tool · GitHub · 165,039 stars

    Stable Diffusion web UI

    Get the code, then follow its README: git clone https://github.com/AUTOMATIC1111/stable-diffusion-webui

  2. ComfyUI

    Open-source tool · GitHub · 112,019 stars

    The most powerful and modular diffusion model GUI, api and backend with a graph/nodes interface.

    Get the code, then follow its README: git clone https://github.com/Comfy-Org/ComfyUI

  3. SwarmUI

    Open-source tool · GitHub · 4,285 stars

    SwarmUI (formerly StableSwarmUI), A Modular Stable Diffusion Web-User-Interface, with an emphasis on making powertools easily accessible, high performance, and...

    Get the code, then follow its README: git clone https://github.com/mcmonkeyprojects/SwarmUI

  4. GPT-Image2-Skill

    Agent skill · GitHub · 3,417 stars

    GPT Image 2 prompt gallery, image prompt library, agentic skill, and CLI for OpenAI image generation/editing

    Get the code, then follow its README to add the skill: git clone https://github.com/wuyoscar/GPT-Image2-Skill

  5. Stable-Diffusion

    Open-source tool · GitHub · 2,750 stars

    FLUX, Stable Diffusion, SDXL, SD3, LoRA, Fine Tuning, DreamBooth, Training, Automatic1111, Forge WebUI, SwarmUI, DeepFake, TTS, Animation, Text To Video, Tutorials...

    Get the code, then follow its README: git clone https://github.com/FurkanGozukara/Stable-Diffusion

  6. fastsdcpu

    Command-line tool · GitHub · 2,114 stars

    Fast stable diffusion on CPU and AI PC

    Get the code, then follow its README: git clone https://github.com/rupeshs/fastsdcpu

  7. LanPaint

    Open-source tool · GitHub · 1,325 stars

    High quality training free inpaint for every stable diffusion model. Supports ComfyUI

    Get the code, then follow its README: git clone https://github.com/scraed/LanPaint

  8. AI-Visual-Prompt-Cookbook

    Open-source tool · GitHub · 489 stars

    Curated collection of reusable JSON prompt templates & style references for AI image generation. Updated daily.

    Get the code, then follow its README: git clone https://github.com/VigoZhao/AI-Visual-Prompt-Cookbook

  9. codex-bridge

    Open-source tool · GitHub · 352 stars

    Image generation (gpt-image-2) and GPT-5 subagents for Claude Code, through the Codex CLI login you already have. No OpenAI API key.

    Get the code, then follow its README: git clone https://github.com/Sateezg/codex-bridge

  10. chatgpt-imagegen

    Agent skill · GitHub · 228 stars

    Use your ChatGPT subscription to generate images from the command line, no OPENAI_API_KEY, no gateway, no daemon. Zero-dep Python CLI + AI-agent skill.

    Get the code, then follow its README to add the skill: git clone https://github.com/leeguooooo/chatgpt-imagegen

  11. Mix-Studio

    Open-source tool · GitHub · 205 stars

    The cleanest, responsive AI workspace. Run highly tuned image and video workflows flawlessly from your desktop or your phone. Built on ComfyUI.

    Get the code, then follow its README: git clone https://github.com/BlackMixture/Mix-Studio

  12. ComfyUI-fal-API

    Open-source tool · GitHub · 200 stars

    Production-ready ComfyUI custom nodes for 1,400+ fal.ai models, auto-updated image, video, audio, LLM and VLM APIs with native media, caching and cost controls.

    Get the code, then follow its README: git clone https://github.com/gokayfem/ComfyUI-fal-API

Questions

What is the best free AI image generator?

Among open-source tools, the most-starred Stable Diffusion interfaces and node editors at the top of this list are the common choices. They are free to run if you have a capable graphics card.

Can I use AI images commercially?

It depends on the model's licence, not the interface. Read the licence of each model you use before you sell or publish work made with it.

Related

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