Online Java Compiler - Free Java Programming IDE

Compile and run Java programs online with our powerful Java compiler. Perfect for learning object-oriented programming, testing Java applications, enterprise development, and academic projects.

What is Java Programming Language?

Java is a high-level, object-oriented programming language developed by Sun Microsystems (now Oracle) in 1995. Known for its "write once, run anywhere" philosophy, Java is platform-independent and runs on the Java Virtual Machine (JVM).

Our online Java compiler provides a complete development environment with JDK support, allowing you to write, compile, and execute Java programs without installing any software. Perfect for learning OOP concepts, enterprise development, and Android app development fundamentals.

Java Compiler Features

Compiler Capabilities

  • Java 17 LTS with latest features
  • Complete Java standard library access
  • Object-oriented programming support
  • Exception handling and debugging

Development Tools

  • Advanced IDE with syntax highlighting
  • Multi-class program support
  • Real-time error detection
  • No installation required

Essential Java Programming Concepts

Object-Oriented Programming

Master classes, objects, inheritance, polymorphism, and encapsulation in Java.

Data Structures

Learn ArrayList, HashMap, LinkedList, and other Java Collections Framework.

Exception Handling

Understand try-catch blocks, custom exceptions, and error handling best practices.

Multithreading

Explore concurrent programming with threads, synchronization, and parallel processing.

Lambda Expressions

Modern Java features including functional programming and stream operations.

File I/O Operations

Handle file reading, writing, and manipulation using Java I/O and NIO packages.

Frequently Asked Questions

Is this Java compiler free to use?

Yes, our online Java compiler is completely free. You can write, compile, and run Java programs without any registration or fees. We support the latest Java features and provide a full development environment in your browser.

Which Java version does your compiler support?

Our online Java compiler supports Java 17 LTS (Long Term Support) with backward compatibility for older Java versions. This includes modern features like var keyword, lambda expressions, streams, and modules.

Can I create multiple classes in my Java program?

Yes, you can create multiple classes in your Java program. However, only one class can be public and contain the main method. All classes should be defined in the same file for our online compiler.

Does the compiler support Java packages and imports?

Yes, you can use all standard Java packages like java.util, java.io, java.lang, etc. However, third-party libraries and custom packages are not available in the online environment.

Is this suitable for learning Java programming?

Absolutely! Our Java compiler is perfect for beginners learning Java and OOP concepts. It provides immediate feedback, detailed error messages, and supports all fundamental Java programming concepts from basic syntax to advanced features.

Can I use this for competitive programming?

Yes, our Java compiler is excellent for competitive programming. It supports fast I/O, collections framework, and all standard algorithms needed for contests like ACM ICPC, Codeforces, and LeetCode.

Are there any execution time limits?

Yes, to ensure fair usage, Java programs have execution time and memory limits. Most educational and practice programs will run without issues. Infinite loops and excessive resource usage will be terminated automatically.

Can I practice Android development concepts?

While you can't run Android-specific code, you can practice core Java concepts that are fundamental to Android development, including OOP principles, data structures, and algorithms that form the foundation of Android programming.