Anthropic at 60%+ AI API market share; 80% of revenue from 1% of customers

Per Ramp business spending data, Anthropic holds roughly 60%+ of business AI API spending market share, with OpenAI at approximately 35%. About 80% of enterprise revenue for both OpenAI and Anthropic comes from just 1% of their customers, a concentration level Ramp says it does not observe in other software categories it tracks. The customer base skews toward tech and AI firms. Coding is described as the most contested area for both companies. OpenAI's adjusted gross margin fell to 33% in 2025, while Anthropic's was approximately 40% in 2025 and is projected at 44% in 2026.

Alex Sacerdote of Whale Rock Capital described how Anthropic employees were spending approximately $100 per day on tokens in early 2025, and said that extrapolated across an estimated 20 million coders worldwide implies a roughly $500 billion market opportunity from coding alone, noting the estimate was based on technology already nine months old at the time. Meta's Muse Code coding agent left beta with a new SDK enabling developers to build custom agents and applications on top of it.