FLUX (Black Forest Labs) review

FLUX is the model family behind many other image apps, and Black Forest Labs sells it directly in three ways: an API, a browser playground and open weights. FLUX 3 Image covers text to image and image to image, with Black Forest Labs pointing to a wide range of styles, highly accurate text rendering and complex prompts. FLUX 3 Image Klein is a 5.6B parameter model designed for editing, with open weights for self-hosting and fine-tuning. API pricing is per image and scales with resolution: Klein costs $0.008 at 768 by 768, while FLUX 3 Image runs from $0.041 up to $0.607 at 4K. For creators this is the cheapest way to generate in bulk if you can work with an API or a tool built on it. It is not a creator app, though: there is no subscription with galleries, brand tools or simple editing, so most non-technical creators will meet FLUX inside Leonardo, Krea or Firefly instead.

Who it is for

Technical creators and developers who want per-image pricing, open weights or to build FLUX into their own tools.

Price

Pay per image via API; FLUX 3 Image Klein from $0.008 per image, FLUX 3 Image from $0.041.

FLUX 3 Image Klein $0.008 /img
Quoted from the vendor pricing page on November 10, 2026.

Key features

• FLUX 3 Image for text to image and image to image
• FLUX 3 Image Klein with open weights, designed for editing
• Highly accurate text rendering and complex prompt handling
• Browser playground with no code required
• Open weights for self-hosting and fine-tuning

Strengths and weaknesses

• Strength: Pay only per image, from $0.008 with Klein
• Strength: Open weights let you run models on your own hardware
• Strength: FLUX models also appear inside Leonardo, Krea and Firefly
• Weakness: No consumer subscription app with editing tools
• Weakness: API setup needs some technical skill
• Weakness: 4K FLUX 3 Image output costs $0.607 per image

Key facts

• Models: FLUX 3 Image, FLUX 3 Image Klein, FLUX 3 Video, FLUX 3 Max
• Certifications: SOC 2 Type II and ISO 27001
• Klein size: 5.6B parameters

Where it ranks

FLUX (Black Forest Labs) is No. 10 in our Best AI Image Generators verdict.