Arena (LMArena)

Arena (formerly LMArena, previously Chatbot Arena) is an AI evaluation platform created by researchers from UC Berkeley. Its website lets users chat with AI models, compare them, and view a leaderboard. The company states its mission is to measure and advance the frontier of AI for real-world use.

What It Is

Arena is a web-based platform for evaluating AI models in practice. Users enter prompts and receive responses from models, with several chat modes: Battle Mode (two anonymous models), Side by Side (two models of the user's choice), Direct (one model at a time), and Agent Mode, which is described as built for complex tasks. The homepage also offers starter prompts such as creating a landing page, building a dashboard, making a browser game, converting a design image to code, building a full-stack app, and launching a storefront.

Leaderboard and Search

The site includes a Leaderboard for viewing model rankings and a Search page for chat history. The About page says the company aims to rigorously measure model performance and deliver real-world value.

Company Background

The About page states that Arena Intelligence Inc. was formed in 2025 and that the company raised funding from investors including a16z and the University of California; the page cites $250 million in venture funding. It lists community channels on Discord, LinkedIn, YouTube, and X. The homepage notes that inputs are processed by third-party AI and responses may be inaccurate.