OpenAI dominates enterprise AI traffic in 2025

_{Figure 1. Top LLM vendors by AI/ML transactions (January 2025–November 2025)}
 

OpenAI has held the top position among LLM vendors by an overwhelming margin to date in 2025, accounting for 113.6 billion AI/ML transactions, more than three times the transaction volume of its nearest competitor. GPT-5’s August release set a new performance bar across coding assistance, multimodal reasoning, and other capabilities that integrate into business functions. Just as importantly, OpenAI’s expanded Enterprise API portfolio (including stricter privacy controls and model-isolation options) has solidified OpenAI and GPT-powered capabilities as the “default engine” behind countless enterprise AI workflows. Everything from internal copilots to automated research agents now lean heavily on OpenAI’s stack, keeping it far ahead of the rest of the field.

OpenAI’s dominance carries important implications for enterprise leaders, which will be explored in greater detail in the upcoming report:

• How vendor concentration impacts risk: The heavy reliance on OpenAI underscores growing vendor dependency within many organizations; transaction flow data shows that businesses may be relying on OpenAI even more than they realize.
• Hidden AI uses across workflows: Transaction categories reveal that LLM interaction is no longer limited to visible tools like ChatGPT. AI underpins everything from automated meeting summaries in productivity suites to behind-the-scenes copilots in common SaaS platforms.

Codeium (Windsurf as of April 2025) emerged as the second-largest source of enterprise LLM traffic in 2025, with strong adoption of its proprietary coding-focused models. As enterprises increased their use of AI in software development, Codeium’s models are a go-to option for engineering teams, especially in secure development environments.

Perplexity rose to the #3 position. Not only an AI-powered search assistant, Perplexity is also an LLM provider offering proprietary large language models that power its answer engine.

Anthropic and Google currently round out the top five LLM vendors by transaction volume. Despite generating only a fraction of OpenAI’s activity, both LLMs played meaningful and differentiated roles in the 2025 enterprise AI landscape. Anthropic saw expanding adoption of its Claude 3 and 3.5 models over the past year, along with a July launch of Claude for Financial Services that further strengthened its position in compliance-heavy environments. Google also accelerated enterprise adoption through major enhancements to Gemini, including improved multimodal capabilities and security and access controls tailored for corporate deployments. It will be interesting to see how the adoption changes as we head into 2026.