Key facts
- Arena raised $200 million in a Series B funding round.
- The company's valuation reached $3.1 billion.
- Arena's valuation nearly doubled in about 10 months.
- The company reported $100 million in annualized run-rate revenue in June.
- Arena's Series A round in January was valued at $1.7 billion.
- Arena introduced its commercial product, AI Evaluations, in September 2023.
Arena, an AI evaluation platform that began as a research project at UC Berkeley in 2023, has secured $200 million in a Series B funding round, bringing its valuation to $3.1 billion. This latest funding nearly doubles the company's valuation from its January Series A round, which valued it at $1.7 billion post-money. The company announced in June that it had reached $100 million in annualized run-rate revenue, up from $30 million at the time of its Series A.
The Series B round was co-led by Lightspeed Venture Partners and Khosla Ventures, with participation from Salesforce Ventures, 01 Advisors, Dell Technologies Capital, Endeavor Catalyst, a16z, and Felicis, among others.
Arena offers a free, crowdsourced platform for consumers to compare AI models. Its commercial product, AI Evaluations, launched in September 2023, provides detailed performance analytics to AI labs and enterprises. The company stated that its timing was opportune as AI labs realized their models were gaming traditional benchmarks, and enterprises sought neutral third-party assessments for their internal needs.
"AI is advancing faster than our ability to evaluate it, and static benchmarks break down once models recognize they’re being tested," the company said in its funding announcement. "The world needs a neutral third party to measure how safe and aligned AI actually is once it’s in the hands of real people. Arena is stepping into that role today."
To further this mission, Arena has introduced an "alignment" category to its leaderboard, ranking models on factors such as unauthorized actions, false attribution, and deceptive completion. Currently, OpenAI's models lead this preliminary alignment leaderboard, with Claude Opus 5.5 and Claude Fable ranking sixth and ninth, respectively.