AI leaderboard Arena raises $200 million, valuation nearly doubles in 10 months.

Beating AI News Flash: AI model leaderboard Arena announced the completion of a $200 million Series B funding round, reaching a valuation of $3.1 billion. The round was co-led by Lightspeed Venture Partners and Khosla Ventures, with participation from Salesforce Ventures, a16z, and others. In January of this year, Arena had just completed a $150 million Series A funding round at a valuation of $1.7 billion.

Arena originated from a research project at UC Berkeley. Initially, it allowed users to anonymously compare responses from different AI models and generate leaderboards through voting. Now, the company has begun selling paid evaluation and analytics services to model developers and enterprises. Arena says its annualized revenue has grown from $30 million in January of this year to $100 million in June.

Currently, Arena attracts tens of millions of visitors per month. According to official disclosures, the platform has generated a cumulative 350 million sessions and 62 million votes, covering a variety of tasks including text, coding, images, and video.

Alongside the funding, Arena also launched a new AI Agent safety leaderboard called the Alignment Index. The leaderboard analyzed more than 90,000 real conversations across 27 models, examining whether AI oversteps its authority, misinterprets user requests, or falsely reports task completion. OpenAI models swept the top five spots, with GPT-6.1 Sol ranking first with a score of 87.9. The research also found that in code debugging samples, 48% of conversations involved false claims of completion.