ALGORIUM
Live 1v1 on Codeforces problems

Duel programmers
in real time

Pick a mode, share a code, and race an opponent through problems neither of you has solved. Verdicts land on the scoreboard the moment Codeforces judges them.

Host a new duelor practise solo →

Blitz

A linear race. Solve the current problem to lock it and unlock the next one for both players.

Lockout

Every problem is open. The first accepted solution claims it permanently.

Classic

Traditional ICPC scoring — most solved wins, with penalty time breaking ties.

Open duels

Host one →

How a duel works

  1. 01

    Host or join

    Set the mode, problem count, rating band and duration — or drop into an open room.

  2. 02

    Solve on Codeforces

    Problems open on Codeforces as normal. Submit there with your own handle.

  3. 03

    Watch it land

    Verdicts are picked up automatically and pushed to both scoreboards live.