The company traces its roots to LMSYS, a UC Berkeley research project that introduced Chatbot Arena in 2023. The platform compares anonymous responses from two AI models, asks users to choose the better answer, and aggregates those selections into Elo-style rankings. Since then, Arena says its community has produced more than 10 million evaluations across tens of millions of conversations from users in more than 150 countries.
Arena incorporated as a company in 2025 after spinning out of the research project. It quickly attracted investor backing, raising a $100 million seed round at a $600 million valuation. The company later raised a $150 million Series A led by Felicis and UC Investments, with participation from Andreessen Horowitz and other investors, bringing its post-money valuation to $1.7 billion. In January, Arena said its annualized revenue stood at $30 million before climbing to its current milestone.
The company said customers pay based on consumption rather than recurring subscriptions, despite describing the milestone as annual recurring revenue.
Arena’s public leaderboard remains free, while its commercial business focuses on providing deeper insights than the rankings available to the public. The company positions its community-generated evaluation data as an alternative to vendor-reported benchmarks, offering AI labs and enterprise customers independently generated performance measurements.
Arena says its evaluation platform now measures models across text generation, coding, vision, image generation, and long-running agent workflows through its Agent Mode feature.
The company says it competes for AI evaluation spending alongside businesses that provide human feedback and data-labeling services used during AI model post-training, including Mercor, Surge, and Scale AI. Arena also noted that crowdsourced model-ranking startup Yupp shut down earlier this year.
Arena was co-founded by Anastasios Angelopoulos, fellow UC Berkeley postdoctoral researcher Wei-Lin Chiang, who serves as chief technology officer, and UC Berkeley professor and Databricks co-founder Ion Stoica, who advised the project before it became an independent company. To date, the company has raised $250 million from investors including Felicis, Andreessen Horowitz, The House Fund, LDVP, Kleiner Perkins, Lightspeed Venture Partners, Laude Ventures, and UC Investments.
This analysis is based on reporting from Crypto Briefing.
Image courtesy of Arena.
This article was generated with AI assistance and reviewed for accuracy and quality.
