Six months after Google DeepMind created the Nobel-winning model AlphaFold 3, the model is now open. The London-based company announced on 11 November that scientists can download the software code and use the artificial intelligence (AI) tool for non-commercial applications.

"We're very excited to see what people do with this," says John Jumper, who leads the AlphaFold team at DeepMind and last month, along with CEO Demis Hassabis, won a share of the 2024 Chemistry Nobel Prize for their work on the AI tool.

AlphaFold3, unlike its predecessors, is capable of modelling proteins in concert with other molecules. But instead of releasing its underlying code — as was done with AlphaFold2 — DeepMind provided access via a web server that restricted the number and types of predictions scientists could make.

Crucially, the AlphaFold3 server prevented scientists from predicting how proteins behave in the presence of potential drugs. But now, DeepMind's decision to release the code means academic scientists can predict such interactions by running the model themselves.

The company initially said that making AlphaFold3 available only through a web server struck the right balance between enabling access for research and protecting commercial ambitions. Isomorphic Labs, a DeepMind spinoff company in London, is applying AlphaFold3 to drug discovery.

However, the publication of AlphaFold3 without its code or model weights—parameters obtained by training the software on protein structures and other data—drew criticism from scientists, who said the move undermined reproducibility. DeepMind swiftly reversed course and said it would make an open-source version of the tool available within half a year.

Anyone can now download the AlphaFold3 software code and use it non-commercially. However, for now, only scientists with an academic affiliation can access the training weights upon request.