The makers of FLUX — frontier open-weights image and video generation models
HQ: Freiburg, Germany | Founded: 2024 | Employees: ~100 (2026, est.) | Stage: Late Stage VC (Series B) | Website: https://blackforestlabs.ai
Black Forest Labs was founded in 2024 in Freiburg, Germany, by Robin Rombach (CEO), Andreas Blattmann, and Dominik Lorenz — the core researchers behind Stable Diffusion at the University of Heidelberg, who had left Stability AI to build a new generation of open image models. The company's founding principle mirrors Stable Diffusion's: release state-of-the-art open-weights models that the ecosystem can build on.
In August 2024 the company launched FLUX.1, an open-weights image generation model family (FLUX.1 schnell, dev, and pro tiers) that immediately set a new quality bar for open image generation, rivaling closed models like Midjourney and DALL-E. It followed with the FLUX.1 Tools suite (Redux, Fill, Depth, Canny) for editing and control, FLUX Kontext for image editing, and FLUX.2 in 2025. A headline partnership with xAI made FLUX the engine behind image generation in Grok, giving Black Forest Labs massive consumer distribution, while its API and enterprise offerings serve developers and businesses.
The company scaled revenue unusually fast for an open-model lab — roughly $96M in annualized revenue by August 2025 (Sacra) — and raised more than $450M in total: a $31M seed led by Andreessen Horowitz (August 2024), a Series A led by a16z in 2025, and a $300M Series B at a $3.25B post-money valuation in December 2025, one of Europe's largest AI raises. With FLUX adopted across Hugging Face, AWS, and countless products, Black Forest Labs is the leading independent open-weights image generation company.
Black Forest Labs assembled the exact team that created Stable Diffusion — Robin Rombach, Andreas Blattmann, and Dominik Lorenz — and immediately became the open-weights image generation standard with FLUX. The company monetizes faster than most open-model labs: ~$96M annualized revenue by August 2025 via its API and enterprise deals, a landmark partnership powering xAI's Grok image generation, and a $300M Series B at $3.25B (December 2025). The bull case is that open models are the default for enterprise and developer image generation, and BFL owns that layer; the bear case is that FLUX must keep winning against an avalanche of competitors (Ideogram, Midjourney, Stability, Google, and video frontier labs) while open-weights economics keep pricing pressure on.
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