Arena (formerly LMArena)
Arena (arena.ai, formerly lmarena.ai) No signup
The catch: Your prompts may be shared with model developers to improve their models and may be visible to the public, so never paste anything private (Arena Privacy Policy).
| Access | No signup |
|---|---|
| Free limits | Terms: 'Company currently offers the Service free of charge.' You can use Arena without logging in, but Direct mode, Side by Side mode, Image Arena and Video Arena need an account; accounts get higher rate limits than logged-out use. Daily credit balance, reset 24 hours after your first prompt; Battle Mode in Text and Code Arena does not use credits. Per-model rate limits; exact numbers not published. |
| Modality | text, code, image, video |
| Credit card | Not required |
| Commercial use | – |
| Trains on your data | Yes, on the free tier |
| Licence or terms | Arena Terms of Use and Privacy Policy |
| Context window | – |
| Model id | – |
| Base URL | – |
| Last checked | 2 Oct 2026 |
How to use Frontier models, side by side
Use it in the browser; there is no API.
Paste into Claude Code
I want to use the free AI model "Frontier models, side by side" from Arena (model id: see the provider docs) in my project. Please: 1. Check the provider docs and give me the exact steps to get a free API key. 2. Give me a minimal working example that reads the key from an environment variable. 3. Tell me the real free limits and any catch (commercial use, card, data use). Listed limits: Free daily credits; numbers not published. 4. If the same provider has a more generous free option, mention it.
Before you ship on it
- Your prompts may be shared with model developers to improve their models and may be visible to the public, so never paste anything private (Arena Privacy Policy).
- Prompts on the free tier may be used to train models. Keep customer data off it.
- Terms of Use (last updated 2026-02-23): you own your Inputs and Outputs, but Arena shows raw outputs of third-party AI services 'for comparison purposes only' and those services' terms apply. No explicit commercial-use…
- Free tiers are shared capacity: treat the limits as a ceiling, not a promise, and keep a paid fallback.
Questions
Is Arena (formerly LMArena) free?
Yes. Arena offers it as no signup, with these limits: Free daily credits; numbers not published. No credit card is needed.
Can I use Arena (formerly LMArena) commercially?
The provider’s terms do not say. Ask them before you build a product on it.
How do I start with Arena (formerly LMArena)?
Use it in the browser; there is no API.
Source: help.arena.ai/articles/5476762589-credit-sytem, checked 2 Oct 2026.