Flux is a family of image generation models built by Black Forest Labs, a company founded by the original researchers behind Stable Diffusion. Rather than shipping as a single consumer web app, Flux ships as a set of models — Flux.1 [schnell] for fast, low-cost generation, Flux.1 [dev] as an open-weight model you can run yourself, and Flux.1/2 [pro] as the highest-quality commercial API tier.

It's aimed at developers and power users who want image generation as a building block rather than a finished app: Flux is integrated into platforms like Replicate, fal.ai, and Together AI for hosted API access, and into ComfyUI and Forge for people who want to run it locally on their own hardware. It's become one of the most widely adopted alternatives to Stable Diffusion and Midjourney in the open-model ecosystem.

Pricing is credit-based and scales with the model tier and output resolution: Flux 2 Dev runs around $0.012 per image, Flux.1 Kontext [dev] around $0.015, and Kontext Pro around $0.04 per image on typical hosting platforms. Because Flux isn't sold directly to consumers, actual pricing depends on which host you access it through.