For the first time, Anthropic has taken the top position in the Ramp AI Index, surpassing OpenAI in verified business adoption. With 34.4% of companies in the panel paying for Anthropic services versus 32.3% for OpenAI, the shift is real and documented by transaction data across more than 50,000 firms.
Key Takeaways
- Anthropic reaches 34.4% enterprise adoption versus OpenAI’s 32.3%, according to the Ramp AI Index
- Anthropic grew 26 percentage points in twelve months, up from just 9% in May 2025
- The lead remains narrow, and experts urge caution about its long-term durability
Transaction data that reshapes the landscape
The Ramp AI Index does not rely on surveys or self-reported usage. It pulls from actual expense data across more than 50,000 companies, making it one of the most grounded measures of enterprise AI adoption available. And what it shows is unambiguous: Anthropic is now the most widely deployed AI provider in business environments, ahead of OpenAI for the first time.
34.4% of companies in the panel are paying for Anthropic services. OpenAI sits at 32.3%. The 2.1-point gap is narrow in absolute terms, but the symbolic weight of the reversal is significant. No previous edition of the Ramp AI Index had placed Anthropic above OpenAI.
OpenAI lost 1% market share over the same period. That decline occurs within a broader context where overall AI product adoption grew 9% across surveyed companies. The market is expanding, and Anthropic is capturing a disproportionate share of that growth while OpenAI appears to be plateauing in its core segments.
A second data point confirms the direction. According to OpenRouter’s leaderboard, OpenAI had already lost its top position in December 2025. The shift is not a one-time anomaly tied to a product launch or a promotional push. It reflects a structural trend that has been building across multiple consecutive months.
The nature of Ramp’s dataset adds credibility to the finding. A company counted in the panel is paying for a service, not just claiming to use it. This transaction filter removes hype and casual experimentation from the measurement. The adoption tracked here is budgeted adoption, which means it reflects deliberate, ongoing commitment.
The Anthropic playbook: technical sectors first
Ara Kharazian, an economist at Ramp, offers a precise account of the dynamics behind the shift. Anthropic began by targeting sectors where teams have the technical depth to integrate LLMs without excessive friction: finance, technology, professional services. Environments where model quality matters more than ease of onboarding.
Claude’s strengths in handling long documents and complex contexts align closely with the demands of legal, financial and technical teams that regularly process large volumes of structured data under time pressure. This fit between the model’s capabilities and the sector’s needs created a natural entry point.
According to Kharazian, Anthropic already holds dominant positions in the highest-adoption groups, including finance, technology and professional services, and its lead is now expanding into other sectors. This pattern of diffusion from technical early adopters toward broader business audiences is a hallmark of durable technology adoption cycles.
Tools like Cowork have also contributed to Anthropic’s expansion by lowering the barrier to adoption for less technical profiles. The starting point was modest: in May 2025, Anthropic was present in just 9% of surveyed companies. Reaching 34.4% in twelve months means nearly quadrupling the client base in a single year.
This trajectory reflects disciplined commercial execution. Rather than pursuing mass adoption from day one, Anthropic consolidated strong positions in high-value niches before using those references to move into more conservative industries. A strategy that diverges sharply from the volume-first approach that defined much of the consumer LLM market.
Also on Horizon:
- Sam Altman on the Stand: The Question of Trust
- Ramp AI Index: Anthropic Edges Out OpenAI in Enterprise
- Claude Code and AI Agents Are Blowing Up Dev Budgets
A lead that still needs to be defended
Experts quoted on the data advise against over-reading the result. A 2.1-point lead is real, but it is fragile. The competition between Anthropic and OpenAI plays out in short cycles, and a well-timed product release or targeted commercial offer can shift rankings faster than annual reports suggest.
OpenAI remains formidable. Its brand recognition with the broader public is unmatched, and its industrial partnerships continue to expand. The 1% decline in the Ramp AI Index is not a collapse. It is a gradual erosion in a market where client loyalty has become more nuanced and more contested.
Anthropic’s transparency on alignment research builds a form of institutional trust that carries weight in enterprise procurement decisions. For compliance, legal and HR teams, a provider that publishes consistent safety research is a meaningful differentiator when evaluating AI vendors for sensitive use cases.
In the short term, the question is whether OpenAI responds with targeted commercial offers or new capabilities aimed at its eroding segments. Over a three-to-six-month horizon, Anthropic’s ability to convert its gains in technical industries into broader adoption in more conservative sectors, healthcare or public administration, will determine whether this top ranking is a milestone or a starting line.
Follow the story on Horizon.
