Hi everyone. I built a Chrome extension that turns Codeforces into a battle arena.

Two players race on the same Codeforces problem inside codeforces.com/battle. Problem on the left, embedded Codeforces editor on the right, shared timer at the top. First Accepted submission wins the round. Best of 3 wins the match.

→ Two modes

• Private rooms. Share code with a friend. Casual, no rating impact.
• Ranked matchmaking. Queue up, get paired with someone within ±500 of your CF rating, results count toward a global Elo leaderboard. Only handles verified with the Codeforces API key can play ranked.

→ Replays

Every round is auto-recorded. language switches, runs, submits. After the match you can scrub through both players side-by-side, see who typed what and when, and flip the replay to public to share a link with anyone. Example: https://api.brawl.world/r/SGeMVTmYHix64jE0wLnvyQ

→ How To Install

It's available on Chrome Web Store: https://chromewebstore.google.com/detail/code-battle/hhjmcfflnibejjnkdnpadgcobbnakkpa

Click "Add to Chrome", then visit https://codeforces.me/battle and sign in with your Codeforces API key (Codeforces > Settings > API).

→ Feedback

First version. Bugs, ideas, all welcome. Drop a comment below or message me directly. Especially looking for early ranked opponents, once you've signed in with the API key just open the matchmaking queue.