Anthropic Overtakes OpenAI in US Business Adoption, Hits 41% in Ramp Index

For the first time, more US businesses are paying for Anthropic's Claude than for OpenAI's ChatGPT, and the gap is widening. The June reading of the Ramp AI Index puts Anthropic at 41 percent of US businesses with paid AI subscriptions, now the single most adopted AI provider in the enterprise. OpenAI, the company that defined the category, held roughly flat. That is a real shift in who the AI race is actually being won with.

Rewind a year and this looked impossible. Anthropic sat around 8 percent of businesses in early 2025. It crossed OpenAI for the first time only in the May reading, when April data showed Claude at 34.4 percent against OpenAI's 32.3. One month later it is at 41. Anthropic has roughly quadrupled its business adoption over the past year while OpenAI's barely moved, growing a fraction of a percent. And the crossover is holding. One month became a trend.

The how is mostly about new buyers. By February, Anthropic was winning around 70 percent of head-to-head matchups among businesses purchasing AI for the first time. Companies coming to AI fresh keep picking Claude, and Anthropic monetizes them hard: roughly 86 percent of its 2025 revenue came from enterprise sales. OpenAI still pulls a larger raw dollar figure from a much bigger consumer base, but on the specific question of which model businesses standardize on, the momentum has clearly flipped.

Now the part that complicates the headline. Ramp measures card spend on paid subscriptions, which leans toward fast-moving smaller firms. A separate IDC enterprise survey from earlier this year tells a calmer story, with OpenAI and Google products used by roughly 42 and 38 percent of large organizations, and only about 19 percent using Claude extensively. So Anthropic leads on paid adoption breadth, while the biggest enterprises are still mostly running OpenAI and Google. Same market, two very different pictures depending on what you count.

The timing matters because both companies are heading for the public market. Anthropic filed confidentially on June 1, OpenAI on June 8, and SpaceX's strong debut on Friday just handed the whole AI cohort a friendlier valuation backdrop. A clean adoption-leader story helps Anthropic's pitch at a roughly 965 billion dollar valuation. But the same report flags the catch: escalating compute costs, capacity constraints, and a token-based pricing model that could squeeze margins as usage scales. Leading on adoption and leading on economics are not the same thing.

So Anthropic finally has the crown it has been chasing, at least on the metric that just flipped. Whether it keeps it depends less on winning the next benchmark and more on whether it can serve all that demand without the costs eating the lead. That is the question the IPO will end up pricing.