Write, compile, and run Java code online for free in the Mentrily playground. No setup required.
Run code instantly in the Mentrily playground.
The Mentrily online Java compiler lets you write, compile, and run Java code directly in your browser. Your program executes in a secure cloud sandbox with standard input support, so it behaves the same way it would in a local terminal — without installing a compiler, IDE, or toolchain.
It is perfect for practicing Java, testing snippets, preparing for coding interviews, and classroom use. Start typing and hit Run — no account required.
Yes. The Mentrily Java compiler is completely free. You can write, compile, and run Java code online without creating an account or installing anything.
No. Your Java code is compiled and executed in a secure cloud sandbox, so it works on any device with a browser — laptops, Chromebooks, and tablets included.
Yes. The playground supports standard input, so programs that read from stdin work the same way they would in a local terminal.
Yes. Create a free Mentrily account to keep your work, or use the built-in question builder to turn a snippet into a shareable practice problem.
Yes. Mentrily is a full teaching platform — educators can build courses and proctored exams with auto-graded Java coding questions, then track learner progress in one dashboard.
Mentrily supports 30+ languages. Jump straight into another playground: