Anthropic has surpassed OpenAI in verified business AI adoption in the US, according to Ramp’s AI Index data from over 50,000 companies. As of April-May 2026, 34.4% of participating businesses paid for Anthropic’s AI services, compared to 32.3% for OpenAI [1, 2].
The gain marks a rapid rise for Anthropic, which held only about 9% of business AI adoption a year earlier, in May 2025. Over that period, OpenAI’s adoption share declined slightly by 1% [1]. Ramp economist Ara Kharazian explained that Anthropic’s growth stemmed in part from increased uptake of its Claude Code offering for software development [2].
“Anthropic has already been in the lead amongst the high adoption groups like finance, tech, professional services,” Kharazian said. “It’s across the other firms where OpenAI still has a lead, but that has been shrinking over the past couple of months.” He added that Anthropic initially focused on a technical customer base and then broadened out through tools like Cowork, which helped drive its success [1].
Kharazian highlighted the AI market’s volatility: “We have never seen a software industry as dynamic, where newcomers can disrupt market leaders in a matter of months,” he said. He cautioned that Anthropic’s current lead may be fragile and should not be seen as a definitive business adoption victory [2].
Ramp’s AI Index analyzes expense data from client companies to serve as a proxy for market trends, though it does not capture the entirety of corporate AI spending [1, 2]. In December 2025, OpenAI last ranked above Anthropic on OpenRouter’s leaderboard [1].
The next data update is expected in the coming months, which will reveal whether Anthropic sustains its lead or OpenAI regains ground as competition intensifies in the enterprise AI sector.
