Just eight months into its commercial operations, Arena—an AI leaderboard provider originally launched as a UC Berkeley research project in 2023—has achieved $100 million in annualized run-rate revenue. The company is best known for its widely used crowdsourced AI model performance leaderboard, which is built from over 10 million user evaluations. On its consumer website, users type a prompt that is sent to two different AI models; they then select which model performed better. While Arena’s popular AI model leaderboard remains free for public use, the company started generating revenue in September when it introduced AI Evaluations. This service offers model labs and enterprises deep-dive performance analytics sourced from the community.

EMBED_PLACEHOLDER_0

Arena’s rapid revenue growth indicates that its commercial offerings resonate as strongly with customers as they do with its community of evaluators, who are often attracted to the platform for early access to the latest—and frequently unreleased—AI models. Although Arena refers to its revenue milestone as ARR, a term traditionally meaning annualized recurring revenue, co-founder and CEO Angelopoulos clarified that the company charges customers for “consumption,” meaning the revenue is not recurring. While Arena has no direct competitors—Yupp, another crowdsourced AI model-picking startup, shut down in March—Angelopoulos noted that the company competes “for the same dollar” with human labeling startups like Mercor, Surge, and Scale AI. These firms help model makers refine their AI during post-training. As AI providers seek to maximize model performance, demand for post-training refinement services continues to surge.

EMBED_PLACEHOLDER_1

When Arena announced in January that it had raised a $150 million Series A at a post-money valuation of $1.7 billion, its annualized revenue stood at $30 million. For comparison, Handshake’s gross annualized revenue from AI training has nearly doubled since January, climbing from $550 million to nearly $1 billion, according to an April report from The Information. Mercor’s annualized revenue also surpassed $1 billion earlier this year, up from $500 million last September, as reported by The Information. Arena ranks models on a range of tasks, including text, coding, vision, and image generation, as well as complex, long-running workflows through its recently introduced Agent Mode.

EMBED_PLACEHOLDER_2

Alongside Angelopoulos, Arena was co-founded by Wei-Lin Chiang, a fellow UC Berkeley postdoctoral student who serves as the startup’s CTO. The company was also co-founded by Ion Stoica, the renowned UC Berkeley professor and Databricks co-founder who advised the project before it was incorporated as a company in April 2025. Arena has raised a total of $250 million from investors, including Felicis, Andreessen Horowitz, The House Fund, LDVP, Kleiner Perkins, Lightspeed Venture Partners, Laude Ventures, and UC Investments.