Overview
Flux is an open-source AI image generation model launched by Black Forest Labs (founded by the original core team members of Stable Diffusion). Upon its release, Flux.1 shocked the AI community with its outstanding image quality and text rendering capabilities, and is considered the "spiritual successor" to Stable Diffusion, surpassing SDXL on multiple metrics.
Flux offers three versions: Flux.1 Pro (closed-source, top-tier), Flux.1 Dev (open-source, non-commercial), and Flux.1 Schnell (open-source, fast version, Apache 2.0, commercial use allowed).
Key Features
- Excellent Image Quality: Reaches new heights in image detail, lighting effects, and overall aesthetics, approaching Midjourney's level
- Powerful Text Rendering: Significantly outperforms SD and DALL·E in rendering text within images, suitable for poster and advertisement design
- Open Source and Deployable: Dev and Schnell versions are open-source, allowing local operation and customization
- Multiple Model Versions: Three tiers: Pro/Dev/Schnell, balancing quality and speed needs
- High Prompt Adherence: Excellent understanding and execution accuracy for complex scene descriptions
- Rapidly Growing Community: Native support in tools like ComfyUI, with rapidly expanding LoRA and workflow ecosystem
Use Cases
- Tech enthusiasts and researchers pursuing the latest open-source image models
- Designers needing to render text in images (posters, logos, etc.)
- Those seeking a free alternative close to Midjourney quality
- ComfyUI users and AI painting workflow builders
- Enterprises needing a commercial open-source model (Schnell version, Apache 2.0)
Pros
- New Benchmark in Image Quality: Highest quality among open-source models, approaching Midjourney
- Leading Text Rendering: Ability to generate text in images far surpasses peers
- Schnell Version Apache 2.0: High-quality open-source model fully usable for commercial purposes
- Fast Generation Speed: Schnell version produces images in just 4 steps
- Original Stable Diffusion Team: Technical strength is guaranteed
Pricing
Flux.1 Schnell is completely free and open-source (Apache 2.0), usable for commercial purposes. Flux.1 Dev is open-source but limited to non-commercial use. Flux.1 Pro is accessed via API, charged per generation. Running Dev/Schnell locally is free but requires a GPU (recommended RTX 4070 12GB or higher).
Summary
Flux is the most noteworthy open-source image model of 2024-2025—its emergence has, for the first time, brought open-source solutions truly close to Midjourney in quality. If you already have experience with Stable Diffusion, it is highly recommended to try Flux. The Apache 2.0 license of the Schnell version makes it an excellent choice for free commercial use by enterprises.
Version History
- Black Forest Labs releases FLUX 3 multimodal model, supporting image, video, audio, and motion prediction (2026-07-24): Black Forest Labs launches FLUX 3 multimodal foundation model via Early Access, using a unified architecture to jointly learn image, video, audio, and motion prediction. The model is extended based on the Self-Flow learning framework, capable of outputting up to 20-second videos with native audio in a single generation, supporting tasks such as text-to-video, image-to-video, and multi-shot concatenation.
- FLUX 3 x mimic: Next-generation video motion model (2026-07-24): Black Forest Labs releases multimodal foundation model FLUX 3, jointly training images, video, and audio, with video prediction accounting for over 95% of training compute. The model collaborates with robotics company mimic to launch FLUX-mimic