'The prize is enormous. The dynamics are shifting.': OpenAI models are the top favorites for enterprise users right now - but Anthropic isn't far behind

• Report finds 78% choose OpenAI models, but many are split over multiple families and generations
• Anthropic started picking up form mid-2025, with 75% using Sonnet/Opus 4.5
• M365 Copilot is still a firm favorite, far outpacing Gemini for Workspace

ChatGPT maker OpenAI remains the most popular model provider chosen by enterprises, according to new data from Global 2000 company CIOs, with virtually four in five (78%) choosing OpenAI's models for production.

However, models from rival companies Anthropic and Google are gaining popularity, with Anthropic uptake picking up from mid-2025.

But more importantly, the data from venture capitalist giant Andreessen Horowitz (a16z) reveals specific use cases will plays the most important role in model decision.