Tools vs. models — what's the difference?
This trips up most beginners. A tool (like ComfyUI or Fooocus) is the interface you install to generate images. A model (like FLUX or Stable Diffusion) is the actual neural network that draws the picture. You install one tool, then load any model into it. Below, we cover the best tools first, then the best models to load into them.
#1 — ComfyUI
ComfyUI is the most powerful and flexible open-source image tool. Instead of a form, you build a visual node graph that gives you total control over every step of the pipeline — and it is the first tool to support new models like FLUX. There is a learning curve, but nothing else matches its power.
Best for: power users, advanced pipelines, and running the newest models day one.
#2 — Stable Diffusion WebUI (AUTOMATIC1111)
AUTOMATIC1111 is the original and most-starred Stable Diffusion interface. It is a straightforward web UI with an enormous ecosystem of extensions, and it remains the reference many tutorials are written for. It has slowed down on the very newest models, but for SD/SDXL work it is still a rock-solid choice.
Best for: the classic Stable Diffusion workflow with the biggest extension library.
#3 — Stable Diffusion WebUI Forge
Forge is a performance-focused fork of AUTOMATIC1111: the same familiar interface, but faster and lighter on VRAM, with better support for modern models like FLUX. If you like the A1111 layout but want more speed, Forge is the upgrade.
Best for: A1111 users who want more speed and lower VRAM use.
#4 — Fooocus
Fooocus is the easiest way to start. It hides all the technical knobs and works like Midjourney: you type a prompt, you get a great image. It is built on SDXL and tunes the settings for you automatically. If you just want beautiful results with zero configuration, start here.
Best for: beginners who want Midjourney-style simplicity, for free and local.
#5 — InvokeAI
InvokeAI is the most professional option, built around a unified canvas for inpainting, outpainting and iterative editing — closer to a real design tool than a prompt box. Its Apache-2.0 license also makes it the friendliest choice for commercial and team use.
Best for: professional editing workflows and commercial-friendly licensing.
#6 — SwarmUI
SwarmUI gives you the best of both worlds: an approachable interface on top of ComfyUI's powerful backend, so beginners get simplicity while power users can drop into the node graph when needed. Its MIT license is the most permissive on this list.
Best for: those who want ComfyUI's power without living in the node graph.
Which model should you run?
Load any of these into the tools above. Model quality has jumped enormously — the best open models now rival Midjourney.
- FLUX (Black Forest Labs) — the current quality leader for open image models: excellent prompt-following, text rendering and realism. The go-to if your GPU can handle it.
- Stable Diffusion 3.5 & SDXL (Stability AI) — the biggest ecosystem by far: thousands of community fine-tunes, LoRAs and controlnets. SDXL runs on modest hardware; SD 3.5 raises quality.
- Qwen-Image (Alibaba) — a strong 2026 open model, especially good at rendering text inside images.
- Sana (NVIDIA) — built for efficiency: sharp images on an 8 GB card, ideal for laptops and older GPUs.
- HunyuanImage (Tencent) — one of the largest open image models, for maximum quality when you have the hardware.
Quick comparison table
| Tool | Interface | Stars (Jul 2026) | License | Difficulty | Best for |
|---|---|---|---|---|---|
| ComfyUI | Node graph | 122k | GPL-3.0 | Advanced | Maximum power & newest models |
| AUTOMATIC1111 | Web UI | 164k | AGPL-3.0 | Medium | Biggest extension ecosystem |
| Forge | Web UI | 13k | AGPL-3.0 | Medium | Faster, lower VRAM |
| Fooocus | Simple form | 51k | GPL-3.0 | Beginner | Midjourney-style simplicity |
| InvokeAI | Canvas | 28k | Apache-2.0 | Medium | Pro editing & commercial use |
| SwarmUI | Hybrid | 4k | MIT | Beginner–Adv. | Power without the complexity |
How to choose
- Complete beginner: Fooocus — install and type a prompt.
- Maximum power / newest models: ComfyUI (or SwarmUI for a gentler start).
- Classic Stable Diffusion + extensions: AUTOMATIC1111 or Forge.
- Professional editing / commercial: InvokeAI.
- Best image quality: any tool + the FLUX model.
Frequently Asked Questions
What is the best open-source alternative to Midjourney?
For Midjourney-style ease, Fooocus. For the highest quality, run the FLUX model in ComfyUI. Both are free and run on your own GPU.
Can I run these without a powerful GPU?
Yes, within limits. Efficient models like Sana and SDXL run on an 8 GB card. The largest models (FLUX, HunyuanImage) want 12–24 GB for comfortable speed.
Are open-source image generators really free?
Completely. The tools and the models are free and open-source. You only pay for electricity and the GPU you already own — there is no per-image charge.
Do they have content filters like DALL·E?
No mandatory cloud filter — you run everything locally, so you control it. That freedom also means you are responsible for using it legally and ethically.
Can I use the images commercially?
Generally yes, but it depends on the specific model's license. SDXL and many community models allow commercial use; always check the license of the exact model (not just the tool) you use.
ComfyUI vs AUTOMATIC1111 — which should I learn?
ComfyUI is more powerful and supports new models first, but has a steeper learning curve. AUTOMATIC1111 (or Forge) is simpler and has more tutorials. Beginners often start with Fooocus, then graduate to ComfyUI.