Anthropic holds 40% of enterprise LLM API spend and OpenAI holds 27%, according to Menlo Ventures’ December 2025 report. Ramp’s transaction data for August 2026 shows 43.8% of U.S. businesses paying Anthropic and 39.8% paying OpenAI.
This guide covers enterprise LLM vendor market share by API spend, paid business adoption, coding workloads, open-weight models, revenue run rates and web traffic, with each metric kept separate.
Enterprise LLM Vendor Market Share Statistics
Anthropic 40%, OpenAI 27%: Enterprise LLM Vendor Market Share by API Spend
Anthropic leads enterprise LLM API spend at 40%, per Menlo Ventures’ 2025 State of Generative AI in the Enterprise report. OpenAI follows at 27% and Google at 21%.
The three vendors account for 88% combined. Meta’s Llama, Cohere, Mistral and a long tail of smaller providers share the remaining 12%.
Menlo derives these shares from estimated dollars spent, based on each model’s proportion of production API usage. The survey covered 495 U.S. enterprise AI decision-makers from November 7 to 25, 2025.
| Vendor | 2023 share | 2025 share |
|---|---|---|
| Anthropic | 12% | 40% |
| OpenAI | 50% | 27% |
| 7% | 21% |
Source: Menlo Ventures, 2025: The State of Generative AI in the Enterprise, December 2025
Anthropic stood at 24% in 2024, the same report shows. Consumer-side numbers for the same vendor appear in these Claude usage trends.
Menlo describes OpenAI as losing nearly half its enterprise share since 2023.
What Did Menlo’s Mid-2025 Reading Show?
Menlo’s July 2025 update put Anthropic at 32%, OpenAI at 25% and Google at 20%. Meta’s Llama held 9% and DeepSeek 1%.
That edition measured share of production usage, not spend, drawing on 150 technical leaders surveyed June 30 to July 10, 2025. It sized model API spend at $8.4 billion by mid-2025, up from $3.5 billion in November 2024.
Only 11% of respondents switched model vendors that year. Another 66% upgraded to newer models from their existing provider.
Source: Menlo Ventures, 2025 Mid-Year LLM Market Update, July 2025
Which LLM Vendor Do U.S. Businesses Pay For Most?
Anthropic, on Ramp’s measure. In August 2026, 43.8% of U.S. businesses on Ramp paid Anthropic for subscriptions or tokens, up 0.34 percentage points from July.
OpenAI reached 39.8%, up 0.09 points. Ramp lead economist Ara Kharazian wrote that new AI adoption is still growing but decelerating.
April 2026 was the first month Anthropic led OpenAI in Ramp’s data, at 34.4% against 32.3%. OpenAI’s adoption had peaked at 36.8% in December 2025.
Buyers often use more than one vendor. In the same April 2026 analysis, 52% of Ramp customers using Anthropic or OpenAI used both, a pattern echoed in the most common AI tools used at work.
Other Vendors in Ramp’s Data
xAI reached 4% of businesses in July 2026, its fastest growth since July 2025. Google stood at 4.5% in Ramp’s analysis of April 2026 data.
Ramp says its data likely undercounts Google, since many businesses get Gemini inside Workspace plans rather than paying for it separately.
Token Prices and Model Mix
Ramp’s effective price per million tokens fell 41% to $0.68 by early September 2026, from a March 2026 peak of $1.15. Frontier models such as Opus, Fable and Sol made up 45% of token share, down from a 53% peak in August.
Source: Ramp AI Index, April, July and August 2026 data (published May to September 2026)
Enterprise Coding: Where Anthropic Holds 54%
Anthropic holds an estimated 54% of the enterprise coding market, against 21% for OpenAI, per Menlo Ventures’ late-2025 data. Its coding share was 42% six months earlier.
Menlo credits this coding position, and Claude Code in particular, for much of Anthropic’s overall enterprise lead. Coding is the largest departmental AI category at $4.0 billion in 2025 spend, 55% of departmental AI spend.
Half of developers now use AI coding tools daily, Menlo found. Application-layer tools built on these models, such as those in Cursor’s adoption figures, are tracked separately from vendor share.
Model performance rankings are another separate lens, covered in recent reasoning benchmark results.
Source: Menlo Ventures, 2025: The State of Generative AI in the Enterprise, December 2025
11% for Open-Weight Models in the Enterprise LLM Vendor Mix
Open-source models held 11% of enterprise LLM API share in late 2025, down from 19% a year earlier, per Menlo Ventures. Llama remains the most widely adopted open-weight model in enterprises.
Chinese open-source models accounted for 1% of total enterprise LLM API usage, about 10% of enterprise open-source.
Menlo’s mid-2025 edition, which measured usage, put open-source at 13% of enterprise workloads and closed-source at 87%.
Ramp’s September 2026 index gives a newer signal: 6.4% of AI-spending businesses and 3.6% of all businesses used model routing platforms. Ramp notes these platforms also serve closed models, so open-source adoption is likely lower.
Source: Menlo Ventures, July 2025 and December 2025 reports; Ramp AI Index, September 2026
How Fast Are Anthropic and OpenAI Revenue Run Rates Growing?
Anthropic’s annualized revenue run rate topped $65 billion at the end of July 2026, Reuters reported, citing a person familiar with the matter. That compares with $47 billion in May and about $9 billion at the end of 2025.
Anthropic’s own Series H announcement on May 28, 2026 confirmed run-rate revenue crossed $47 billion earlier that month.
OpenAI’s run rate reached $40 billion, CNBC confirmed on August 14, 2026. CFO Sarah Friar told investors enterprise revenue now exceeds consumer revenue, after the company entered 2026 at a 60-40 split.
The New York Times reported on September 18, 2026 that Anthropic is pacing above $100 billion in annual revenue, per Axios. Bloomberg described the same report as a full-year 2026 expectation, so that figure is not charted.
A run rate projects annual revenue from current sales levels. It is not booked annual revenue.
Source: Reuters, August 17, 2026; Anthropic, May 28, 2026; CNBC, August 14, 2026
Gen AI Web Traffic Share Is Not Enterprise LLM Vendor Market Share
Similarweb tracks worldwide visits to generative AI websites. Mobile apps and desktop clients are not included, and the data does not measure API spend or business adoption.
| Platform | 12 months earlier | August 2026 update |
|---|---|---|
| ChatGPT | 73.3% | 55.5% |
| Gemini | 12.9% | 25.6% |
| Claude | 1.9% | 9.3% |
| DeepSeek | 4.0% | 3.4% |
| Grok | 2.6% | 2.4% |
| Copilot | 2.0% | 1.6% |
| Perplexity | 2.0% | 0.9% |
Source: Similarweb, Gen AI website traffic share update, August 2026 (posted September 7, 2026)
ChatGPT held 55.5% of gen AI website visits in the August 2026 update, down from 73.3% twelve months earlier. More on its audience sits in these ChatGPT user figures.
Gemini rose from 12.9% to 25.6%, and Claude from 1.9% to 9.3%. App-level counts for Google’s assistant appear in separate Gemini user statistics.
FAQs
Which company has the largest enterprise LLM market share?
Anthropic. Menlo Ventures estimates it held 40% of enterprise LLM API spend in late 2025, ahead of OpenAI at 27% and Google at 21%.
Is Anthropic ahead of OpenAI in business adoption?
Yes, on Ramp’s measure. In August 2026, 43.8% of U.S. businesses on Ramp paid Anthropic, against 39.8% for OpenAI. Anthropic first passed OpenAI in Ramp’s April 2026 data.
What is Google’s share of the enterprise LLM market?
Google held 21% of enterprise LLM API spend in Menlo Ventures’ late-2025 estimate, up from 7% in 2023. Ramp says its own data likely undercounts Gemini because many firms get it through Workspace.
How much enterprise LLM usage goes to open-source models?
Open-source models held 11% of enterprise LLM API share in Menlo Ventures’ late-2025 report, down from 19% a year earlier. Chinese open-source models accounted for 1% of total enterprise usage.
Do Reddit threads reflect real enterprise LLM market share?
No. Reddit discussions are anecdotal and self-selected. Measured data comes from Menlo Ventures’ survey-based spend estimates and Ramp’s business transaction data, which both show Anthropic ahead of OpenAI.
Sources
https://menlovc.com/perspective/2025-the-state-of-generative-ai-in-the-enterprise/
https://menlovc.com/perspective/2025-mid-year-llm-market-update/
https://ramp.com/data/ai-index-sept-2026
https://www.anthropic.com/news/series-h
https://commandlinux.com/statistics/chatgpt-vs-gemini-vs-claude-usage-market-share/
