61 languages · one editor

Write in any language. Get a judge verdict in milliseconds.

A real compiler in your pocket: write code on your phone, run it against your test cases, and see per-test verdicts with full stdout and stderr.

C+main.cpp · GCC▶ Run

1#include <iostream>
2int main() {
3    int a, b;
4    std::cin >> a >> b;
5    std::cout << a + b;
6}

ACAccepted3/3 · 12 ms

Everything you need to write, run and test code on a phone

Built for competitive programming practice, interviews and quick experiments.

C, C++, Python, Java, Go, Rust, Kotlin, JavaScript and many more, with several versions each. Syntax highlighting for 46 of them.

Up to 100 test cases per run, each graded AC, WA, TLE, MLE, RE, CE, with a line-by-line diff when the output is wrong.

Live results as each test finishes, full stdout and stderr, custom stdin, and compile errors you can tap to jump to the line.

Up to 20 extra files in one workspace, with per-language hints on how to import them.

Examples and classic problems with ready-made test cases and starter solutions in many languages.

Projects are saved on your phone. Runs started offline are queued and sent when you're back online.

Until then, the same judge runs in your browser: pick a language, paste your code, and run it against your tests.