34.4% versus 32.3%, the gap isn't large but the signal is strong—enterprise AI procurement is shifting from "choosing OpenAI because everyone uses it" to "using whichever tool is most convenient and cost-effective," the era of multiple vendors has truly arrived. Claude Code's penetration in code and documentation scenarios is indeed aggressive, with 70% of the Fortune 100 integrated, creating a deep moat.

AIMPACT reports that in April 2026, Anthropic’s enterprise AI adoption rate first surpassed OpenAI’s 32.3%, reaching 34.4%, and became the market leader. The U.S. enterprise adoption rate reached 50.6%, with reliance on large-model tools rising rapidly. Claude’s monthly API calls exceeded 25B, with about 45% coming from enterprise users. Anthropic’s growth is driven by advantages such as Claude Code in software development and document-intensive workflows, with deep penetration in industries including finance, legal, and R&D; more than 70% of the Fortune 100 are using Claude. The market is shifting from brand-led competition to multi-vendor competition driven by performance and cost; as switching costs decrease, share fluctuations intensify, and the leading advantage may reverse in the short term.