Online Java Compiler

The Online Java Compiler lets you write, compile, and run Java code instantly in your browser — no setup, no JDK installation. Just type your code in the editor, hit Run, and see the output right away. This free online compiler for Java supports a modern JDK, real-time input (stdin), and lets you save and share your code from any device.

Whether you're learning Java, testing a quick program, or solving a coding problem, this online Java compiler gives you a fast, reliable place to compile and execute code without configuring anything on your computer.

How to Use the Online Java Compiler

1. Type or paste your Java code into the editor. Make sure your code includes a public class with a main method.
2. If your program needs input, enter each value on a separate line in the User Input (Stdin) box.
3. Click Run to compile and execute your code.
4. View the result instantly in the Output terminal.
5. Switch between light and dark themes, and copy or download your output anytime.

Your code is compiled and run on a current JDK, so modern Java syntax and standard libraries work out of the box.

Why Use an Online Java Compiler

• No installation needed. Skip the JDK setup and run Java directly in your browser on any laptop, desktop, or phone.
• Great for learning and practice. Test ideas, run examples, and check your output without leaving the page.
• Save and share your code. Store your work in the cloud and open it from any computer with an internet connection.
• Fast and lightweight. A clean editor that loads quickly and stays out of your way.
• Interactive input. Provide real-time inputs through the stdin box, just like a local terminal.

Features of This Online Java Compiler

• Compiles and runs Java on a modern JDK
• Real-time program input through the stdin box
• Light and dark editor themes
• One-click copy and download for your output
• Cloud save and code sharing
• Beginner-friendly, clean, and distraction-free interface

A Quick Note on Java

Java is a general-purpose, object-oriented programming language first released by Sun Microsystems in 1995. It's known for its "write once, run anywhere" design: Java code is compiled into bytecode that runs on the Java Virtual Machine (JVM), so the same program works across different operating systems. Today Java powers Android apps, enterprise software, web backends, and large-scale systems, which is why it remains one of the most widely used languages in the world.

If you're starting out, an online Java compiler is one of the easiest ways to begin: you write a small program, run it, and learn from the output in seconds — without installing a full development environment.

Frequently Asked Questions

Is this Online Java Compiler free? Yes. You can write, compile, run, save, and share Java code completely free, with no account required to get started.

Which Java version does the Online Java Compiler support? It runs on a current JDK, so modern Java syntax and common standard libraries are supported.

Do I need to install the JDK? No. Everything compiles and runs in your browser, so there's nothing to download or configure.

Can my Java program take user input? Yes. Enter your inputs in the stdin box before running, with each input on its own line. Your code can read them using Scanner or BufferedReader.

Why does my code need a public class and a main method? Java programs start running from the main method inside a class, so your code must include public static void main(String[] args) for the compiler to execute it.

Can I run other languages here too? Yes. Along with Java, the platform supports languages like Python, C, C++, JavaScript, PHP, Ruby, TypeScript, Bash, and more.