Overview
Flux is an open-source AI image generation model developed by Black Forest Labs (founded by former core team members of Stable Diffusion). Upon its release, Flux.1 amazed 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
- Exceptional Image Quality: Reaches new heights in image detail, lighting effects, and overall aesthetics, approaching Midjourney 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 ecosystems
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 with quality close to Midjourney
- ComfyUI users and AI art workflow builders
- Enterprises needing commercial open-source models (Schnell version Apache 2.0)
Pros
- New benchmark in image quality: highest quality among open-source models, close to Midjourney
- Leading text rendering: significantly outperforms peers in generating text within images
- 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 assured
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, with pricing based on generation count. Running Dev/Schnell locally is free but requires a GPU (recommended RTX 4070 12GB or above).
Summary
Flux is the most noteworthy open-source image model of 2024-2025—its emergence has allowed open-source solutions to truly approach Midjourney in quality for the first time. 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 发布 FLUX 3 多模态模型，支持单次生成 20 秒视频与原生音频 (2026-07-24): Black Forest Labs has launched the FLUX 3 multimodal foundation model in Early Access, adopting a unified architecture for joint learning of images, video, and audio. This model is built on the Self-Flow learning framework, enabling the generation of up to 20-second videos with native audio in a single output, and supports tasks such as text-to-video, image-to-video, and multi-shot concatenation.
- FLUX 3 x mimic：新一代视频动作模型 (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, which has been tested and deployed on Audi's production line. After incorporating action prediction, video generation quality initially drops by up to 10%, but recovers to original levels after 3,500 steps of training.
- FLUX 3 Multimodal (2026-07-24): Unified architecture combining image/video/audio, generating 20-second videos with native audio in a single pass; FLUX-mimic deployed on production lines in collaboration with a robotics company
- FLUX 2 / FLUX 2 Pro (2026): Black Forest Labs' second-generation flagship: further upgraded parameters and image quality, forming an open-source vs. closed-source standoff with Midjourney v8 / Imagen 4 after multiple iterations; simultaneously launched FLUX 2 Tools series (Fill / Depth / Canny / Redux)
- FLUX 1.1 Pro / 1.1 Pro Ultra (2024-2025): Introduced 4 MP ultra-high-definition mode and Raw realistic photography mode, with prompt adherence superior to SDXL
- FLUX.1 Pro / Dev / Schnell (2024-08): FLUX series debut: Pro closed-source top-tier, Dev open-source non-commercial, Schnell Apache 2.0 commercial, hailed as the 'spiritual successor to Stable Diffusion'