OpenAI is narrowing the gap with Anthropic among U.S. business users, according to the latest Ramp AI Index released this week.
The data, which covers more than 70,000 American businesses that spend billions via Ramp's bill pay and corporate card products, shows Anthropic still leads with nearly 44% of eligible businesses paying for its services in July, compared to OpenAI's nearly 40%. But OpenAI has been growing faster in Q3 to date, potentially signaling a shift after Anthropic first overtook OpenAI in May with 41% versus 39%.
According to Ramp economist Ara Kharazian, OpenAI's growth has been fueled by GPT-5.6 Sol, which he called "really good" and "increasingly the choice for developers." Meanwhile, Anthropic's higher-end Fable 5 model has "disappointed both in adoption and real-world application given price plus data retention requirements imposed by regulators," Kharazian posted on X.
The data reveals a key insight about enterprise AI spending: it is remarkably volatile. Businesses are willing to switch between providers as each lab releases new models, a pattern that should give both companies' investors pause about how sticky enterprise AI spending really is.
Notably, the overall AI adoption rate among Ramp customers continues to climb — it topped 50% in March and reached nearly 56% by July — meaning both companies should be growing revenue even as they fight for market share.
The data comes as both OpenAI and Anthropic are approaching planned IPOs that would reveal their true financial positions. Ramp's data, while not a complete picture of the market (it excludes large enterprises using tools from providers like American Express), provides one of the few independent signals about how the enterprise AI race is playing out.
