Which Dart SDK version?

Dart 3.x — the current stable line with null safety on by default.

Can I run Flutter here?

No — Flutter needs a UI target. This runtime is dart-vm console apps.

Are pub packages available?

No — sandbox has no network to fetch packages. Bring source only.

Dart · online compiler

Run Dart online

Run Dart 3 online — the Flutter language, browser-hosted.

Available versions

Dart 3.7 Dart 3

Firecracker microVM live per-test verdicts multi-file compile

Dart is Google's language for Flutter — a modern, null-safe, JIT/AOT-compiled language optimized for UI development but perfectly capable of general-purpose work. Since Dart 3 the null safety and pattern matching are excellent.

ls-judge runs Dart 3.x with the standard SDK inside a Firecracker microVM. This is Dart-VM console execution — no Flutter UI, but everything you need for algorithm work or CLI utilities.

Starter code

What you get in Dart

Clicking "Run now" opens the playground with this exact code and a matching test case pre-loaded — passes on first Run.

dart

Dart 3.7

import 'dart:io';
void main() {
  final n = int.parse(stdin.readLineSync()!.trim());
  print(n * 2);
}

stdin →

expected →

FAQ

Common questions about Dart on ls-judge

Which Dart SDK version?: Dart 3.x — the current stable line with null safety on by default.
Can I run Flutter here?: No — Flutter needs a UI target. This runtime is dart-vm console apps.
Are pub packages available?: No — sandbox has no network to fetch packages. Bring source only.
Is it free?: Yes.