Stability AI is a British artificial intelligence company best known for developing Stable Diffusion, an open-source text-to-image model that lets users generate photorealistic images from written prompts. The company is headquartered in London and was founded in 2019 by Emad Mostaque, a former hedge fund analyst, along with a group of researchers and developers. It is incorporated in the U.S. as well, with a presence in San Francisco.
Stable Diffusion, released publicly in 2022, distinguished itself from competing image-generation tools by being open-source — meaning the underlying model weights were made freely available for anyone to download, modify, and deploy. That decision accelerated adoption among developers and researchers and seeded a wide ecosystem of third-party applications built on top of the model. It also prompted debate about the risks of releasing powerful generative AI without access controls, particularly around the potential for misuse in creating synthetic media.
Beyond image generation, Stability AI expanded into other modalities, releasing models for audio, video, language, and biological research applications such as protein structure prediction. The company positioned itself as a champion of open AI development, in contrast to competitors that keep their models proprietary.
Stability AI raised roughly $101 million in a funding round in 2022 at a valuation reported at the time to be around $1 billion, making it one of the more prominent startups in the generative AI wave that drew significant investor attention following the public release of large language models and image-generation tools. The company has faced financial and leadership turbulence since its founding, and Mostaque stepped down as CEO in 2024. The open-source Stable Diffusion models remain widely used and actively developed by the broader research community regardless of the company's internal changes.