Arena Team

Created by researchers from UC Berkeley’s SkyLab, Arena (formerly LMArena) is an open platform where everyone can easily access, explore and interact with the world’s leading AI models.

Arena-Rank: Open Sourcing the Leaderboard Methodology

Arena-Rank: Open Sourcing the Leaderboard Methodology

Building community trust with open science is critical for the development of AI and its alignment with the needs and preferences of all users. With that in focus, we’re delighted to publish Arena-Rank, an open-source Python package for ranking that powers the LMArena leaderboard!

Studying the Frontier: Arena Expert

Studying the Frontier: Arena Expert

Arena Expert is a great way to differentiate between frontier models. In this analysis, we compare how models perform on 'general' vs 'expert' prompts, focusing on 'thinking' vs 'non-thinking' models.

Arena's Ranking Method

Arena's Ranking Method

Since launching the platform, developing a rigorous and scientifically grounded evaluation methodology has been central to our mission. A key component of this effort is providing proper statistical uncertainty quantification for model scores and rankings. To that end, we have always reported confidence intervals alongside Arena scores and surfaced any

Arena Expert and Occupational Categories

Arena Expert and Occupational Categories

The next frontier of large language model (LLM) evaluation lies in understanding how models perform when challenged by expert-level problems, drawn from real work, across diverse disciplines.

Re-introducing Vision Arena Categories

Re-introducing Vision Arena Categories

Since we first introduced categories over two years ago, and Vision Arena last year, the AI evaluation landscape has evolved. New categories have been added, existing ones have been updated, and the leaderboards they power are becoming more insightful with each round of community input.

New Product: AI Evaluations

New Product: AI Evaluations

Today, we’re introducing a commercial product: AI Evaluations. This service offers enterprises, model labs, and developers comprehensive evaluation services grounded in real-world human feedback, showing how models actually perform in practice.

Nano Banana (Gemini 2.5 Flash Image): Try it on LMArena

Nano Banana (Gemini 2.5 Flash Image): Try it on LMArena

“Nano-Banana” is the codename that was used on LMArena during testing for what is now known as: Gemini 2.5 Flash Image. Try it for yourself directly on LMArena.ai