LMArena Raises $100M to Rethink How the World Measures AI Performance

LMArena just locked in $100 million in seed funding to rebuild how we judge artificial intelligence. The round was led by a16z and UC Investments, with Lightspeed, Laude Ventures, Felicis, Kleiner Perkins, and The House Fund all in the mix. The funding arrives right before the relaunch of LMArena’s platform next week—a cleaner, faster, mobile-first version of its already widely used AI evaluation hub.

Over 3 million votes have been cast on more than 400 AI model evaluations so far, feeding insights to models from OpenAI, Google, Meta, xAI, and others. The idea is to create something neutral and reliable that actually reflects how people use AI, not just benchmarks in a lab.

“In a world racing to build ever-bigger models, the hard question is no longer what can AI do. Rather, it's how well can it do it for specific use cases, and for whom,” said Anastasios N. Angelopoulos, co-founder and CEO at LMArena.

The update isn’t just cosmetic. LMArena’s new platform will include a rebuilt interface, saved chat history, endless chat support, lower latency, and an improved experience that works better on mobile. All new innovation will take place on the refreshed lmarena.ai, though the original version will remain live for now.

Investors say the company is building trust, not just tools. The evaluations are open, the methods are public, and every model is tested using diverse, real-world prompts. That transparency is core to how LMArena wants to shape AI’s future.

“We invested in LMArena because the future of AI depends on reliability,” said Anjney Midha, General Partner at a16z.

LMArena’s long-term plan is to offer advanced analytics and enterprise services, but keep public access and community participation free. The company is already working with model makers to catch edge-case bugs, test fine-tunes, and surface real-time feedback from human users.