LMSYS Chatbot Arena
Benchmarks & Leaderboards · Free + paid
Human-preference LLM ranking via pairwise comparisons
At a glance
- Made by
- Arena AI
- Korean
- None (English and a few others only)
- Available on
- Web
- Open source
- Apache-2.0
- GitHub
- 39,549 stars · Apache-2.0
What is LMSYS Chatbot Arena?
Arena (arena.ai) is an LLM leaderboard site that benchmarks and compares AI models. It offers Battle mode, which pits two anonymous models against each other; Side by Side, which compares two models of your choice next to each other; Direct, which lets you chat with a single model; and Agent mode for complex tasks. The FastChat platform behind it is described as an open platform for training, serving, and evaluating LLM chatbots, which collects human head-to-head votes to build an online LLM Elo leaderboard.
- Battle mode: two anonymous models compete
- Side by Side: compare two models of your choice
- Direct: chat with one model
- Agent mode: for complex tasks
- Leaderboard (LLM Elo ranking based on human votes)
- Starter examples for building landing pages, dashboards, games, and full-stack apps
Who uses LMSYS Chatbot Arena and for what
- Compare responses from multiple AI models yourself and pick one
- Check LLM rankings (leaderboard)
Pricing
Free (public benchmark/leaderboard)
Mostly free leaderboards/datasets released for academic and community purposes
Estimate based on AI knowledge - please verify on the official site
AI tools similar to LMSYS Chatbot Arena (alternatives)
LMSYS Chatbot Arena vs. alternatives at a glance
| AI | Pricing | Combos on the map | Connected tools | Free | Cheapest monthly | Korean |
|---|---|---|---|---|---|---|
| LMSYS Chatbot Arena | Free + paid | 0 | 1 | — | — | No |
| OpenRouter Rankings | Free + paid | 0 | 1 | Yes | — | No |
1 of these 2 tools have a free plan.
Combo and connection counts are based on the relationships recorded on AI Galaxy Map (2026-10-26); they are not a quality ranking.
LMSYS Chatbot Arena on AI Galaxy Map
- One of 27 AI tools in the Benchmarks & Leaderboards field.
- Connected to 1 other tools — #26 in its field.
Frequently asked questions
Can I use LMSYS Chatbot Arena for free?
Free (public benchmark/leaderboard). Prices can change, so check the official site before paying.
What AI can I use instead of LMSYS Chatbot Arena?
Tools that do the same job, such as OpenRouter Rankings, are connected to it on the map.
Can I use LMSYS Chatbot Arena in Korean?
None (English and a few others only)
Sources (official pages)
Checked on the official pages on 2026-10-14. Prices and features can change, so check the official site again before paying.