Black Forest Labs's original FLUX.1 launch offered downloadable image-generation models with different usage terms. FLUX.1 schnell was released under Apache 2.0, while FLUX.1 dev was described as an open weightsA model whose trained parameters are published for anyone to download and run — unlike API-only models you can access but never possess.Full definition → model for noncommercial applications, with commercial arrangements handled separately. The August 2024 announcement makes that distinction explicit.
For developers choosing a version to run themselves, access to the weights was only part of the decision. The intended application also had to fit the terms attached to that particular variant.
Terms in this piece · Glossary
open weights — A model whose trained parameters are published for anyone to download and run — unlike API-only models you can access but never possess.
distillation — Training a small, cheap model to imitate a big one's outputs, keeping much of the capability at a fraction of the cost.
