What Is FLUX?
FLUX is a next-generation image generation model developed by Black Forest Labs. The team, which includes the creators of Stable Diffusion, has created a model with FLUX that produces higher quality, better text understanding, and more natural images. Launched in 2024, FLUX has surpassed its competitors particularly in photographic realism and text rendering.
Key features of FLUX: - **Text understanding:** Can understand complex and long prompts very well - **Text rendering:** One of the most successful models at writing text within images (signs, posters, etc.) - **Natural appearance:** Fewer errors in human faces, hands, and anatomy - **Diverse styles:** Wide range from photography to illustration, anime to 3D rendering
FLUX Variants
FLUX comes in three different versions:
**FLUX.1 Schnell (Fast):** - Apache 2.0 license (free, open for commercial use) - Can generate images in 1-4 steps - The fastest version, ideal for real-time applications - Small quality trade-offs but huge speed advantage - Recommended for local use and personal projects
**FLUX.1 Dev (Developer):** - Open weights, free for non-commercial use - Produces high-quality images in 20-30 steps - Offers quality closest to the Pro model - Can be used in ComfyUI and other local interfaces - Can be fine-tuned by the community
**FLUX.1 Pro:** - Accessible only via API (Replicate, fal.ai, Together AI) - Highest quality - Suitable for commercial use - For enterprise projects and production environments
Prompt Writing Techniques
FLUX is a model that understands natural language prompts very well. Instead of comma-separated tag lists like in other models, you can use flowing sentences:
**Tag style (old method):** "beautiful woman, long hair, sunset, beach, photorealistic, 8k, professional photo"
**Natural language (ideal for FLUX):** "A young woman with flowing long hair walks along a sandy beach at sunset. The warm golden light illuminates her face as gentle waves crash behind her. Shot in the style of a professional fashion editorial with shallow depth of field."
FLUX prompt tips: - Describe the scene in detail, tell a story - Clearly specify lighting conditions - Specify camera angle and lens type ("shot on 35mm lens", "aerial drone perspective") - Use double quotes if you want to add text: a sign that reads "Hello World" - Negative prompts are generally not needed, FLUX produces clean outputs
Parameter Settings
**Recommended settings for FLUX.1 Dev:** - Steps: 20-30 (20 is sufficient for most cases) - CFG: 1.0 (FLUX works with low CFG, guidance of 3.5-7 is recommended) - Sampler: Euler - Scheduler: Normal or Simple - Resolution: 1024x1024, 1024x768, or 768x1024
**For FLUX.1 Schnell:** - Steps: 1-4 (4 steps gives the best quality) - CFG: 1.0 - Other settings the same
Note: FLUX exhibits different CFG behavior from Stable Diffusion models. High CFG values (7+) lead to poor results. Instead, use the "guidance" parameter.
API Usage
If you want to use FLUX via API, there are several options:
**Replicate:** You can run FLUX models directly on the Replicate platform. Python example:
- Install the replicate library with pip - Set your API token - Call the model with the replicate.run function - Send prompt and parameters as input
**fal.ai:** fal.ai offers lower pricing and fast inference. You can develop real-time applications with WebSocket support.
**Together AI:** An affordable alternative for batch operations and high-volume usage.
FLUX LoRA and Fine-Tuning
You can teach your own style or concept by training LoRA on the FLUX model:
- **AI Toolkit (kohya):** The most popular tool for FLUX LoRA training - **Training time:** Approximately 1-2 hours with 8GB+ VRAM (for 20-30 images) - **Data preparation:** 15-30 images with consistent style and quality is sufficient - **Ready LoRAs on Civitai:** Hundreds of community-trained FLUX LoRAs are available
FLUX.2 and the Future
Black Forest Labs is working on FLUX.2. Expected innovations: - Higher resolution (native 2K and 4K support) - Video generation integration - Better character consistency - Improved inpainting and outpainting - Multi-language support (improvement in non-English prompts)
Common Mistakes and Solutions
The most common mistake when using FLUX is using high CFG values. Users accustomed to Stable Diffusion who use CFG values of 7-12 get distorted results with FLUX. In FLUX, the CFG value should be 1.0, and instead you should use the "guidance" parameter between 3.5-7.
Another common mistake is using short tag-style prompts designed for SD 1.5. FLUX understands natural language sentences much better; instead of "beautiful woman, long hair, sunset," describe the scene in a complete sentence.
Choosing the wrong model version is also frequent. Schnell is speed-focused and should be used with low step counts, while Dev is quality-focused and requires 20-30 steps. Mixing settings between these two versions causes poor results.
FAQ (Frequently Asked Questions)
**Is FLUX or Midjourney better?** Both have different strengths. FLUX stands out for being open source and running locally; it is very strong in text rendering and photographic realism. Midjourney leads in artistic quality and ease of use. We recommend FLUX for photographic work and Midjourney for artistic projects.
**How much VRAM does FLUX require?** The FLUX.1 Dev model requires a minimum of 8GB VRAM, with 12GB+ recommended. The Schnell version is lighter and can run with 6GB. You can also run it on lower VRAM cards using ComfyUI with "--lowvram" mode.
**Does text rendering with FLUX really work?** Yes, FLUX is currently the most successful open-source model for text rendering. Specify the text to be written in double quotes in your prompt and it usually renders correctly. Short words or slogans produce the best results rather than long sentences.
FLUX Versions and Differences
The FLUX family offers multiple models: FLUX.1 [dev] is the open-source developer version, FLUX.1 [schnell] is the fast generation model, and FLUX Pro is the premium version optimized for commercial use. The Dev version is free but Pro license is required for commercial projects.
FLUX's strongest advantage is photorealism: it produces more consistent results than competitors in human faces, hands, and natural scenes. It's also superior to Midjourney in text generation.
Common Mistakes
- Choosing wrong version: Prefer Pro for commercial use, Dev for experimentation - Setting CFG scale too high: 3-5 is optimal for FLUX - Neglecting negative prompt: Specify unwanted details via negative prompt - Excessive step count: 25-35 steps is sufficient for most scenarios
FAQ
**Is FLUX or Midjourney better?** FLUX excels in photorealistic results and text generation, while Midjourney leads in artistic quality and aesthetics. Choose based on your use case.
**Can I run FLUX locally?** Yes, FLUX Dev version can be run through ComfyUI or Automatic1111. Requires minimum 12GB VRAM, 16GB+ recommended.