How can we help you?

Click 'Start Free' on the homepage, fill out the registration form with your email and password, and verify your email address to get started.

AlgoArena supports 18 languages, including JavaScript, Python, Java, C++, C#, Go, Rust, and TypeScript. You can select your preferred language in the code editor during battles.

Your ranked Elo increases when you win live human ranked battles and decreases when you lose them. The amount of change depends on the skill difference between you and your opponent.

Our matchmaking system pairs you with opponents of similar skill levels based on ranked Elo, ensuring fair and competitive battles.

If you disconnect, you have 2 minutes to reconnect. If you don't return, the battle is forfeited and your opponent wins.

Yes! Visit the Practice section to solve problems at your own pace without affecting ranked Elo.

Free includes unlimited ranked battles, the full practice library, and community features, plus a monthly allowance of Rena AI assistance.

Open Settings > Subscription and pick Pro or Ultimate. Pro adds larger monthly Rena budgets for hints, chat, and code review; Ultimate makes Rena chat and mock interviews unlimited.

Yes, you can cancel your subscription at any time from your account settings. You'll retain Pro features until the end of your billing period.

Try refreshing the page or clearing your browser cache. If the issue persists, switch to a different browser or contact support.

Check your spam folder and ensure notifications are enabled in your account settings. Add contact@algoarena.net to your contacts.

Battles are first-to-pass: the first player to pass all tests wins. If the timer runs out, the stronger partial result (more tests passed) takes it. Review the detailed feedback in your battle history.