Academic side project to $600M startup in 2 years.

LMArena raised $100M seed at $600M valuation, led by a16z and UC Investments.

What it is: Platform behind Chatbot Arena where users vote on AI model responses in blind comparisons.

Key metrics:
• $100M seed (largest in AI evaluation)
• 3.5M+ human preference votes
• 400+ models evaluated
• 1M+ monthly visitors

How it happened:
• Started as UC Berkeley PhD side project in 2023
• Built simple blind comparison tool under LMSYS
• Major AI labs began using for pre-release testing
• Became go-to AI model leaderboard
• Spun out as company in April 2025

Takeaway: Solve real infrastructure problems, market comes to you.

https://techcrunch.com/2025/05/21/lm-arena-the-organization-behind-popular-ai-leaderboards-lands-100m/