FLUX.1 Pro

FLUX.1 Pro is the flagship, closed-weight model in Black Forest Labs’ FLUX family, released in August 2024 alongside the open FLUX.1 dev and schnell tiers. It’s a 12 billion parameter rectified flow transformer, the largest and highest-quality version in the lineup, available only through Black Forest Labs’ own API and hosting partners such as Replicate and fal.ai rather than as downloadable weights. Black Forest Labs was founded in 2024 by researchers who previously built Stable Diffusion at Stability AI, and FLUX quickly became one of the strongest text-to-image models for prompt adherence, typography, and image composition, competing with Midjourney and OpenAI’s image models. Pricing is usage-based per generated image rather than a flat subscription, aimed at developers building image generation into products rather than casual end users. Since the initial release, Black Forest Labs has layered additional Pro-tier capabilities on top, including the Kontext editing models, while keeping FLUX.1 Pro as the general-purpose flagship for straight text-to-image generation.