LM Arena, Recently Criticised for Favouring Major AI Firms, Raises $100 mn

LM Arena, the organisation behind widely used AI leaderboards, has secured $100 million in seed funding, bringing its valuation to $600 million, according to Bloomberg.

Launched in 2023 and primarily operated by researchers affiliated with UC Berkeley, LM Arena has become a central hub for evaluating AI models.

The platform is used by major players like OpenAI, Google, and Anthropic to test and showcase their latest systems.

The round was led by Andreessen Horowitz (a16z) and UC Investments, with participation from Lightspeed Venture Partners, Felicis Ventures, and Kleiner Perkins.

"We’re focused on building a neutral, open, community-driven platform that helps the world understand and improve the performance of AI models on real queries from real users," the platform said in an X post.

Previously supported by grants and donations from backers such as a16z, Google’s Kaggle, and Together AI, LM Arena has recently faced criticism over alleged favoritism in its rankings—claims the organisation has strongly denied.

A paper titled 'The Leadership Illusion' from researchers claims LM Arena gave companies like Meta, OpenAI, Google, and Amazon a competitive advantage on the leaderboard, while rival firms were not given the same opportunity.

The paper—authored by researchers from Stanford, MIT, Cohere and AI2 accuses LM Area of favouring select tech giants by allowing them to test multiple model variants privately and selectively publish results.

For example, Meta tested 27 models before Llama 4’s release; however, only one model's score—among the top-ranked—was publicly disclosed, the paper said.

In addition to the funding news, LM Arena has teased a major update: a full platform relaunch is coming next week. The revamped version promises a fresh new design built entirely on community feedback, aiming to enhance usability, transparency, and the overall evaluation experience.