FLUX.1 Pro

FLUX.1 Pro launched on August 1, 2024 alongside Black Forest Labs itself, the startup founded by the core Stable Diffusion researchers. It is a 12-billion-parameter rectified-flow transformer noted at launch for photorealism, strong prompt adherence, and unusually good text rendering inside images — quality widely compared to Midjourney v6 and DALL-E 3. It powered xAI's Grok image generation at launch and was picked up by Mistral's Le Chat, and it remains the reference point the open FLUX.1 [dev] and [schnell] variants are distilled from. Pro is proprietary and API-only: no weights, served through BFL's own API and partners including fal.ai, Replicate, Together AI, and Freepik. Honest caveats: BFL has not disclosed the training data, which leaves open the same copyright questions hanging over most frontier image models, and per-image API pricing makes high-volume use a real budget line.

BFL-reported: leading ELO scores on the Artificial Analysis image leaderboard (1.1 Pro); launch-era human-preference tests vs Midjourney v6 and DALL-E 3 with ~800 judges (provider-reported)