AI · Web app

Arena AI

Crowdsourced benchmarking platform and free chat interface for frontier AI models.

Visit arena.ai ↗

Arena AI (formerly LMSYS Chatbot Arena) is an open evaluation platform that ranks LLMs based on blind human preference. It lets you run side-by-side prompt battles between anonymous models, compare specific models side-by-side, or use direct chat with top commercial and open-weight models for free.

What it's for

  • Test and compare outputs from top frontier models using the same prompt
  • Access commercial LLMs like Claude, GPT, and Gemini for free without individual subscriptions
  • Vote on blind model comparisons to contribute to public AI leaderboards
  • Evaluate coding and reasoning performance across different model architectures

Features

  • Battle Mode: Compare anonymous models side-by-side and vote on the better response
  • Side by Side: Manually choose two specific models to compare side by side
  • Direct Chat: Converse with a single selected model directly
  • Agent Mode designed for testing complex multistep tasks
  • Public ELO leaderboard ranking LLMs, coding, and vision models

Pricing

Free to use via web interface

Details

Type
Web app
Category
AI
Topic
Model Comparison
Open source
Yes
Platforms
Web
For
Developers, AI researchers, and general users wanting to test top AI models without paid accounts.
Alternative to
ChatGPT, Claude, Google Gemini
Tags
llm, benchmarking, chatbots, arena, leaderboard, lmsys

Why it was saved

  • @theaisurfer, 11 January 2026: Under 'Direct Chat' or 'Side by Side', it gives free direct access to top frontier models (Claude, Gemini, Grok, GPT) to test and compare outputs without paid subscriptions.

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Updated