[ LANGUAGE — JAVA 21 ]
Run Java online. No install.
Compile and run Java online. Practice OOP, data structures and exam problems with zero setup.
Sample — copy into the compiler
import java.util.*;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Your name: ");
System.out.println("Hello, " + sc.nextLine() + "!");
}
}1. Open the Java runtime
Go to the compiler and select Java. Your code persists per language.
2. Paste and add input
Copy the sample or type your own. Fill stdin if the program reads input.
3. Run and share
Press Run in the editor, then copy the page URL to share your exact state.
Java FAQ
Do I need to install Java to use this?
No. The Java 21 runtime runs in your browser via CodeLab's embedded editor. Open the compiler, pick Java, and press Run.
Is running Java online free?
Yes. The CodeLab Playground is free with no account. Optional paid plans add privacy and larger limits — see the pricing page.
How do I handle input in Java?
Use the stdin panel inside the editor for piped input, then press Run. The sample below reads a name from stdin.