Free Online Java Compiler
Write, Compile & Run Java Code
The best online Java compiler for students and developers. No installation needed. Supports Java 8, 11, 17, 21. Compile and execute Java code instantly in your browser.
public class Main {
public static void main(String[] args) {
System.out.println("Hello, World!");
}
}🏫 Trusted by students at IITs, NITs, and 500+ engineering colleges across India
Choose Your Java Version
Compile Java code with any LTS version — switch anytime
Why Students in India Choose JavaCompiler.in
Built for the needs of Indian students and developers
No Installation Needed
Works on college lab computers without admin rights. Perfect for GATE, BCA, MCA, B.Tech students.
Works on Mobile Data
Optimized for Jio, Airtel, and other Indian mobile networks. Code on any Android or iOS device.
Placement Prep
Prepare for TCS NQT, Infosys InfyTQ, Wipro, Cognizant placement tests with real Java practice.
University Curriculum
All programs aligned with the Anna University, AKTU, VTU, JNTUH Java syllabus.
Why Use an Online Compiler Instead of Downloading Java?
No 500MB JDK Download
Skip the heavy JDK download. Our compiler runs Java on the cloud — 0 MB on your device.
Works on Any Computer
College labs, shared PCs, Chromebooks — works everywhere with a browser.
Always Up to Date
No version conflicts. Switch between Java 8, 11, 17, 21 with a single dropdown.
Share Code with One Link
Save your code and share a unique URL with classmates or teachers.
Why Choose Our Java Compiler?
Everything you need to write, compile, and run Java programs online
Lightning Fast
Compile and run Java code in less than 2 seconds with our optimized servers.
Mobile Friendly
Code on any device - phone, tablet, or desktop. Fully responsive editor.
Save & Share
Save your code to the cloud and share with a unique URL. Access anywhere.
Zero Setup
No download, no installation, no configuration. Just open and start coding.
How to Use Our Java Compiler
Get started in 3 simple steps - no signup required
Write Your Code
Type or paste your Java code in the editor above. Syntax highlighting helps you write error-free code.
Click Compile & Run
Press the green "Run" button or use Ctrl+Enter to compile and execute your program.
See Output Instantly
View the output in the console below. Any errors will be highlighted with line numbers.
Popular Java Programs
Ready-to-run programs covering all essential Java concepts
Online Compiler vs Desktop IDE
See why students prefer our online compiler
| Feature | JavaCompiler.in | Desktop IDE |
|---|---|---|
| Installation | ❌ None needed | ✅ Required |
| Access Anywhere | ✅ Browser-based | ❌ Single device |
| Setup Time | ⚡ 0 seconds | ⏱️ 30+ minutes |
| Mobile Support | ✅ Full support | ❌ Limited |
| Syntax Highlighting | ✅ Yes | ✅ Yes |
| Auto-save | ✅ Automatic | Manual |
| Cost | 💰 Free forever | 💸 May require license |
Learn Java From Scratch
60+ comprehensive tutorials covering basics to advanced topics
Frequently Asked Questions
Everything you need to know about our online Java compiler
What is an online Java compiler?
An online Java compiler is a web-based tool that lets you write, compile, and execute Java programs directly in your browser without installing any software. It runs Java code on remote servers and displays the output instantly.
Do I need to install Java to use this compiler?
No! Our online compiler runs Java programs on our servers. You only need a web browser and an internet connection to write and run Java code.
Which Java versions are supported?
We support Java 8, Java 11, Java 17, and Java 21 (LTS versions). You can select your preferred version from the dropdown menu in the compiler.
Can I save and share my Java code?
Yes! You can save your code and get a unique URL to share with others. Your code will be stored securely and can be accessed anytime.
Is this Java compiler free to use?
Yes, our online Java compiler is 100% free. There are no hidden charges, no signup required, and no limitations on the number of programs you can run.
Can I use this compiler on mobile devices?
Absolutely! Our compiler is fully responsive and works on smartphones and tablets. You can code on any device with a web browser.
How fast is the compilation?
Our compiler typically compiles and executes Java programs in less than 2 seconds. We use optimized servers to ensure fast execution times.
What are the limitations of this online compiler?
Programs have a maximum execution time of 15 seconds and memory limit of 256MB. Network access and file system operations are restricted for security reasons.
Is my code secure?
Yes, your code is transmitted over HTTPS and executed in isolated containers. We do not store or share your code unless you explicitly save it.
Can I take input from the user in my program?
Yes! You can use Scanner class or BufferedReader to take input. Enter your input in the "Input" section before running the program.
Can I use this for GATE exam preparation?
Absolutely! Our compiler is perfect for GATE CSE preparation. Practice Java programs, test algorithms, and verify your solutions instantly.
Is this suitable for BTech/BCA/MCA students?
Yes! Students from IITs, NITs, and 500+ engineering colleges across India use JavaCompiler.in for their Java programming assignments and practice.
Does it work with slow internet connection?
Yes, our compiler is optimized for low bandwidth. It works smoothly on Jio, Airtel, and other mobile data connections common in India.
Can I practice for TCS NQT / Infosys InfyTQ on this?
Yes! Many students use our compiler to prepare for placement tests at TCS, Infosys, Wipro, Cognizant, and other IT companies.
Is there a dark mode for the editor?
Yes! Click the moon icon in the compiler toolbar to switch to dark mode. The dark theme is easy on the eyes for long coding sessions.
Ready to Start Coding?
Join 500K+ students who trust JavaCompiler.in for their Java programming journey.
Open Java Compiler - It's Free!