Arena AI

Arena AI is a free model comparison platform where people chat with AI models side by side and vote on which answer is better, producing the widely cited Arena leaderboards. Formerly called Chatbot Arena and then LMArena, it started as a UC Berkeley research project and dropped the "LM" from its name in January 2026. What makes it different from benchmark sites is that rankings come from real people judging real prompts while the models stay anonymous.

What is Arena AI used for?

Arena AI is used by curious users who want free access to strong models, by developers choosing a model for a product, and by labs testing new releases.

• Running Battle mode, where two anonymous models answer the same prompt and you pick the winner
• Choosing specific models and comparing their answers side by side
• Checking leaderboards for text, web development, vision, documents, search, image, video and agents
• Trying new or unreleased models that appear under codenames
• Generating web apps, landing pages and small games from a prompt to compare coding models

Who Arena AI is best for

Arena AI suits developers and product managers picking a model, AI enthusiasts who follow new releases, researchers using its public datasets, and anyone who wants to try frontier models for free. It is not a good fit for confidential work, because prompts may be shared with model providers, and it is not built as a daily personal assistant with memory or projects.

Arena AI pricing

Arena AI is free to use for chatting, comparing and voting, and its FAQ describes it as an open space for everyone. The company says it is funded through AI evaluation services sold to enterprises, model labs and developers, which are priced privately. No consumer subscription was listed as of October 2026.

Limitations to keep in mind

• Do not paste sensitive data: prompts and votes are collected for research, and conversations may be shared with model providers in de-identified form
• After each vote models are resampled, so earlier context may not carry over
• Crowd preferences reward answers people like, which is not the same as factual accuracy on every task
• Only votes cast while models are anonymous count toward rankings

Arena AI vs alternatives

Artificial Analysis is the better resource when you want measured speed, price and benchmark data rather than human preference votes. Poe is better for daily use of many models with saved chats and bots. OpenAI Playground suits developers testing one lab's models with full parameter control. Together Chat is a simple way to chat with open models. Arena AI wins when you want blind, head-to-head comparisons and the crowd-ranked leaderboards that many in the industry track.

Tips for getting started with Arena AI

Use your real everyday prompts in Battle mode, since that tells you more than generic test questions. Vote before you look at model names to keep your judgment honest. Check the category leaderboard that matches your use case, such as WebDev for front-end coding, instead of only the overall ranking.

Arena AI FAQ

Is Arena AI free?

Yes. Arena AI is free to use for chatting with models, side-by-side comparisons and voting. The company earns money from evaluation services for labs and enterprises.

Is Arena AI the same as LMArena?

Yes. Arena AI is the rebranded LMArena, which itself began as Chatbot Arena. The platform moved to arena.ai and dropped the "LM" in January 2026.

How are Arena AI leaderboards calculated?

Rankings use votes cast while models are anonymous, fed into a Bradley-Terry rating system similar to Elo. Votes made after names are revealed do not count.

Is it safe to share private information on Arena AI?

No. Arena collects prompts and votes for research and may share de-identified conversations with model providers, so avoid entering confidential data.