Microsoft and Anthropic Form Alliance: Claude becomes the first leading language model available from all three cloud giants

Having recently revised its agreement with longtime partner OpenAI, Microsoft pledged to invest billions of dollars in Anthropic, one of OpenAI’s top competitors.

What’s new: Microsoft, Anthropic, and Nvidia formed a partnership. Microsoft and Nvidia will invest up to $10 billion and $5 billion, respectively, in Anthropic. Microsoft will make Anthropic models available on its cloud platform, and Anthropic will purchase $30 billion of inference processing on Microsoft’s infrastructure. Further terms, including whether some of the investments are optional or conditional on Anthropic’s performance, were undisclosed.

How it works: The deal makes Anthropic’s Claude the only top model family to be available on all three leading cloud services: Microsoft, Google, and Amazon. It also gives Anthropic’s valuation a big boost.

• Claude Sonnet 4.5, Claude Haiku 4.5, and Claude Opus 4.1 are available in a preview on Microsoft Foundry. Microsoft also integrated the models into Excel’s agent mode, enabling them to build, edit, and evaluate spreadsheets.
• Anthropic committed to buy inference capacity on Azure and contract up to 1 gigawatt of additional capacity on its Nvidia Grace Blackwell and Vera Rubin hardware at an undisclosed price. This is similar to the “tens of billions” in capacity Anthropic contracted to buy from Google in October.
• Nvidia and Anthropic will work together to develop Anthropic models to work on Nvidia hardware and optimize Nvidia GPUs for Anthropic models. Claude previously ran primarily on Amazon or Google hardware.
• The investments value Anthropic at about $350 billion, up from its $183 billion valuation in September, according to CNBC.

Behind the news: Microsoft’s 2022 partnership with OpenAI set the stage for Anthropic’s 2023 alliance with Amazon, matching one startup AI company with an established cloud provider. But Anthropic’s later agreements with Google and OpenAI’s recapitalization and restructuring of its relationship with Microsoft made it easier for Microsoft and Anthropic to find common ground.

• An October revision of the earlier agreement between Microsoft and OpenAI gave Microsoft a 27 percent stake in OpenAI’s new, for-profit subsidiary and 20 percent of OpenAI’s revenue until that company achieves AGI, as determined by a panel of experts. Microsoft can use OpenAI’s models until 2032, but that right is not exclusive, and OpenAI can work with cloud providers for some operations.
• In September, Microsoft made Claude models available in its Copilot coding assistants and Microsoft 365 productivity suite. Subsequently, it allowed them to access documents and emails stored in its cloud.
• As early as fall 2023, Microsoft sought to reduce its dependence on OpenAI and develop its own cutting-edge AI capabilities. A year later, the relationship had frayed as OpenAI sought to restructure and forged a separate cloud deal with Oracle. Meanwhile, Microsoft hired Inflection AI co-founder Mustafa Suleyman to integrate its AI technology into consumer products.
• In October 2023, Anthropic agreed to train its models exclusively on Amazon’s infrastructure for up to $4 billion. The same month, Anthropic partnered with Google for $2 billion, making Google its inference partner for Claude.

Why it matters: A few years ago, OpenAI was the rising AI star in need of processing power, and Microsoft needed both technology to compete with peers and customers for its Azure platform. Their partnership, in which Microsoft invested $17 million over a few rounds, served both companies. Today, however, OpenAI needs more processing power than Microsoft will provide, while Microsoft needs to diversify its AI offerings. Meanwhile, Anthropic’s models have become so popular, especially among the business customers that Microsoft typically caters to, that they make a good match for Microsoft’s cloud offerings. An investment in Anthropic, even at a heightened valuation, puts Microsoft (and Nvidia) in line to benefit as AI continues to go mainstream.

We’re thinking: Wheeling and dealing aside, developers increasingly have access to the model they want, on the cloud platform they want. This is good news for everyone who hates being locked into a single choice.