Anthropic Says It Never Sought to Ban Open Weights, but Backs Distillation Crackdowns and Pre-Release Testing

Anthropic published a formal position on open-weight models after days of speculation that it wanted them restricted. In the statement, the company says it has never advocated banning open weights as a category and supports releasing models without dangerous capabilities as a public good. Chief executive Dario Amodei reinforced that in interviews, saying he does not oppose open weights but is concerned about the strategic gains of Chinese open models.

The disagreements will center on the details. Anthropic favors evaluating each dimension of openness separately and applying more scrutiny as capability rises. Amodei told CNBC and Axios he supports chip export controls, a crackdown on distillation, and mandatory safety testing for all sufficiently capable models, whether open or closed. He singled out biology, arguing that whether a model can help weaponize pandemic-class pathogens is an empirical question for pre-release testing rather than an assumption. The company is not releasing an open-weight version of Claude.

The timing is not incidental. The clarification arrives the same week that Kimi K3 topped open-weight rankings and Washington threatened Moonshot, and while a broad group of United States firms publicly backed open models. Anthropic, the lab most associated with a safety-gated closed strategy, is defining a middle position that keeps its own weights closed while it argues over which capabilities warrant control.