Ever felt the urge to code in Java but didn’t have your trusty IDE around? Maybe you’re on vacation, maybe you’re just away from your computer for the day. Don’t worry, you’ve got options. There are tons of free online Java compilers that let you code Java anywhere right from your browser. No downloads, no hassle.

In this post, we’ll cover 12 of the best free online Java compilers so you can code on the go. Whether you’re a beginner just starting out with Java or an expert programmer brushing up on your skills, these online IDEs have you covered.

11 Free Online Java Compilers are:

1. Ideone Java Compiler
2. CoderPad
3. Repl.it
4. Codiva
5. JavaTPoint
6. GDB Online
7. Browxy
8. CodingGround by TutorialsPoint
9. Paiza.io
10. Jdoodle
11. CompileJava.net

Let’s dive in and start coding!

Why Use an Online Java Compiler?

Why bother with an online Java compiler when you can just download a full IDE? A few good reasons:

• Convenience. You can code Java anywhere with an internet connection. No need to install anything or carry around a laptop. Just open your browser and you're ready to go.

• Quick tests. If you want to try out some Java code real quick to test something, an online compiler is perfect. No setup required.

• Learning tool. For beginners, an online compiler is a great way to learn Java. You can follow tutorials and see the results of your code right away. No struggling with installations and configurations to distract you.

• Share code easily. Need help debugging some code? With an online compiler, you can share a link to your code with others to collaborate.

• Stay up-to-date. Online compilers typically update to the latest version of Java regularly. So you'll always have the option to use modern language features without worrying about updating your local environment.

• Minimalism. If you like to code without the distraction of a full IDE, an online Java compiler gives you a minimalist coding environment with just an editor and compiler.

With so many free options, there's no reason not to give an online Java compiler a try. Whether you're learning the ropes, need to quickly test some code, or just prefer a minimal coding experience, these tools have got you covered.

1. Ideone - Neat and Simple Interface

If you're looking for a simple, no-frills online Java compiler, Ideone is a great option. It has a clean, minimal interface that lets you focus on your code.

To get started, just go to the Ideone website and start typing or pasting your Java code into the editor. Ideone supports all the latest versions of Java, from Java 5 to Java 14. Once you've entered your code, click the "Compile & Run" button. Ideone will compile your code and display the output. If there are any errors, it will show you the exact line numbers so you can debug easily.

Ideone is perfect for:

• Quickly testing snippets of Java code

• Sharing code samples on forums, blogs or with colleagues

• Practicing Java programming exercises or interview questions

Some other useful features in Ideone include:

• Custom input - You can provide your own input data to pass to the program

• Time and memory limits - Set limits to avoid infinite loops or out of memory errors

• Multiple files - Ideone supports compiling multiple Java files together

• Popular libraries - Use libraries like Scanner, ArrayList, etc.

• Save and share - You can save your programs to access later or share with others.

Overall, Ideone is a simple but effective online Java compiler.

It may lack some advanced features of other sites, but its minimal interface and support for the latest Java versions make it a great option for quickly compiling and running your Java code from anywhere.

2. CoderPad - For Interviewing Java Developers

If you’re looking to hire Java developers, CoderPad is a great resource for conducting coding interviews. CoderPad provides an online code editor where interviewers and interviewees can collaborate in real time.

As the interviewer, you’ll set up a CoderPad “room” and share the link with your candidate. In the room, you’ll both have access to a code editor to work through Java programming problems together. You can watch as the candidate writes code to solve the problems, and provide guidance and feedback along the way.

This allows you to thoroughly evaluate a candidate’s Java skills, problem-solving abilities, and communication in a coding environment.

For candidates, CoderPad is a chance to demonstrate your Java chops in an authentic way. You’ll get to code up solutions to real-world Java problems, ask clarifying questions, and discuss your code with the interviewer. While coding in CoderPad, be sure to think out loud as much as possible so the interviewer can understand your thought process.

CoderPad supports standard Java library imports as well as Maven and Gradle if you want to use external dependencies.

CoderPad provides a collaborative, in-browser coding environment for Java without needing to download any software. It’s a useful tool for quickly assessing Java developers’ skills during the interview process.

For both interviewers and candidates, CoderPad allows you to have an interactive coding conversation and gain valuable insight into someone’s Java abilities.

Overall, CoderPad is a helpful resource for interviewing and hiring talented Java developers.

3. Repl.it - Browser-Based IDE

Want to code Java without downloading anything? Replit is a free online IDE that lets you write and run Java code right in your browser. You don’t need to install any software or Java development kits to get started.

Replit has a simple, minimal interface so you can focus on coding. When you open a new Java repl, you’ll see an editor on the left and a console on the right. The editor is where you write your Java code. The console shows the output of your program and any error messages.

To run your code, just press the play button at the top of the page. Replit will compile your code and run it, displaying the output in the console. If there are any errors, it will show you the error messages to help you fix them.

Replit has a few useful features for learning Java:

• Automatic indentation: Replit automatically indents your code as you type to keep it neat and readable.

• Line numbers: The editor shows line numbers so you can easily reference specific lines of code.

• Syntax highlighting: Replit highlights different parts of your Java code in different colors to make the syntax easier to understand.

• Code completion: As you type, Repl.it shows suggestions to autocomplete variables, methods, and keywords. Just press Tab to accept a suggestion.

• Revision history: Replit automatically saves revisions of your code so you can see how it changed over time and revert back to previous versions if needed.

Overall, Repl.it is a great tool for learning and practicing Java. Give it a try and start coding right away in your browser!

4. Codiva - Share and Embed Java Code

Codiva lets you share and embed your Java code in web pages. If you've written a cool Java program and want to show it off or share how it works, Codiva is an easy way to do that.

You simply paste your Java code into the editor on the Codiva website. Then you can get an embed code to add to your own website or blog. Anyone visiting that page will see your Java code nicely formatted and highlighted, and they'll be able to execute it and see the output right on the page.

For example, say you wrote a simple Java program to print "Hello World!". You can paste that into Codiva, get the embed code, and add it to your website. When someone visits your site, they'll see your Java code for the Hello World program, and when they click "Run", they'll see "Hello World!" printed below it.

• Share Java code on your website or blog

• Embed interactive code that visitors can execute

• Promote Java programming by showing how cool it can be

• Demo your Java skills by sharing code you've written

Codiva also gives you a shareable link for your code that you can post on forums or social media. Anyone following that link will be taken to the Codiva editor with your code loaded and ready to run.

So if you're looking for a simple way to share your Java code creations with the world, give Codiva a try. Just paste in your code, get the embed code or shareable link, and spread it wherever you like!

JavaTPoint Java Compiler

Javatpoint online Java compiler is a useful tool for anyone learning or working with the Java programming language. It allows you to write Java code directly in the browser and compile and run it with a simple click.

Some key points about the Java compiler on Javatpoint:

• It is completely free to use. You don't need an account or registration to access the compiler.
• The interface is simple and intuitive. You just enter your Java code in the top text area, choose a version of Java, and click "Compile" or "Run".
• It supports both compiling and running your Java code directly in the browser, allowing you to quickly test and debug as you write programs.
• It can compile and run basic to intermediate Java programs with no issues. I didn't encounter any compiler errors while testing simple programs. • The output is displayed right below the code, showing any compiler errors, warnings and the program output when you run it. • It is a good tool for learning Java syntax and language basics since you get instant feedback when you make mistakes.

The free to use, instant feedback nature makes it ideal for learning and practicing Java programming.

GDB Online - Debug Java Programs Online

When coding in Java, bugs and errors are inevitable. To fix them, you'll need to debug your code. One of the best ways to debug Java programs online is with GDB Online.

GDB Online is a free, open-source online debugger for Java. It allows you to step through your code line by line, inspect variables, set breakpoints, and make changes on the fly. Using GDB, you can catch bugs early and solve issues quickly without needing to download any software.

To get started, simply paste your Java code into the editor on the GDB Online website. Then, you can:

• Set breakpoints by clicking on the line number in your code. Execution will stop at that line so you can examine the state of your program.

• Step through your code line by line using the Step Into, Step Over and Step Out buttons.

• Inspect the values of variables by hovering over them.

• Make changes to your code and re-run it instantly. No need to stop the debugger or recompile.

• Use the Console view to print statements or test snippets of code.

GDB Online supports most Java language features, including generics, lambdas and streams. It uses the OpenJDK to compile and run your Java code, so you get an experience very similar to developing on your local machine.

For those times when you need to debug complex Java code on the go, GDB Online provides a simple yet powerful solution.

Browxy

Browxy is another free online Java compiler that lets you compile and run Java code right in your browser. It has a simple, clean interface that's easy to use.

To get started with Browxy, just go to browxy.com and you'll see the editor window. You can either type or paste your Java code into the editor, then click the "Compile" button. If there are no errors, your code will compile successfully and you'll see the output in the window below. If there are any issues, you'll get error messages to help you debug your code.

Browxy supports the latest versions of Java, so you can use newer language features without issue. It also has some handy features like:

• Auto-complete to help you code faster. As you type, Browxy will suggest potential completions of classes, methods, variables, and keywords.

• Real-time error highlighting. Browxy will instantly highlight any syntax errors, typos or other issues in your code to make it easy to fix them.

• Code snippets and examples. If you get stuck, Browxy has a selection of code snippets and short examples you can refer to for help.

• Share and download options. When you have code you want to share or use elsewhere, you can generate a shareable link or download your code as a .java file.

Overall, Browxy is a great free option if you want to practice Java coding in your browser. Whether you're just learning Java or you're an experienced developer, Browxy has the essential tools you need to code, compile and run programs on the go.

CodingGround by TutorialsPoint

If you're looking for a simple yet effective online Java compiler, CodingGround by TutorialsPoint is a great option. This free service lets you compile and run Java code without having to download an IDE.

To get started, just go to the CodingGround website and select Java as your programming language. You'll be taken to the Java editor where you can type or paste your Java code. Once you've entered your code, hit the Compile & Run button. If there are no errors, your output will be displayed. This makes CodingGround ideal for quickly testing snippets of Java code or running small Java programs.

Some other useful features of CodingGround include:

• Syntax highlighting to make your code easier to read

• Explanations and examples for many Java concepts and libraries

• The ability to save and share your Java programs

• Support for the latest versions of Java (currently up to Java 14)

• A clean, simple interface without any ads

While CodingGround may lack some of the advanced features of desktop IDEs like Eclipse or IntelliJ, its simplicity and ease of use make it a great tool for learning and experimenting with Java. Whether you're a beginner just getting started with the language or an experienced developer looking to quickly test some code, CodingGround has you covered.

Give CodingGround a try the next time you want to run some Java code. Between its simple interface, useful features, and extensive Java documentation, you'll find it a very capable and convenient online IDE.

paiza.IO

Paiza.IO is one of the popular free online Java compilers which allows you to write and execute Java programs right in the browser. It has a simple and clean interface where you can start coding instantly.

To get started, just go to the paiza.IO website and select Java as the language. You'll see an editor open up where you can type or paste your Java code. Once you've written your program, simply click the "Run" button to compile and execute it. If there are any errors, they will be shown in the output window so you can debug your code.

Paiza.IO also offers some handy features like:

• Syntax highlighting to make your code more readable

• Auto-completion to save you time typing

• Sample programs to help you learn

• The ability to save and manage multiple programs

Whether you're just learning Java or brushing up on your skills, paiza.IO is a great resource to code and run Java programs right in your browser for free. Give it a try and start programming today!

For those interested, paiza.IO offers additional languages like C++, C#, Python, Ruby and more. So you have options to code in your language of choice.

JDoodle - Fast and Easy to Use

If you're looking for a simple way to code Java on the go, JDoodle is a great option. This popular online compiler lets you write and run Java code right in your browser. No need to download an IDE or mess with setup - just start coding!

JDoodle has a clean, intuitive interface that's perfect for beginners. You can choose between their basic editor or a more full-featured IDE experience. Either way, the platform is fast and responsive, compiling your code in seconds so you can quickly debug and improve your programs.

An added bonus is that JDoodle supports almost 70 languages, so you can also code in C++, Python, C#, and more. Whether you're practicing for a coding interview, completing a school assignment, or just learning to code for fun, JDoodle has you covered.

To get started, just head to JDoodle.com and start writing your code in the editor. Then click “Run” and your program will compile and execute, showing the output instantly. If there are any errors, JDoodle provides clear messages to help you troubleshoot.

With a simple, intuitive interface and support for nearly any language you want to learn, JDoodle is an easy, powerful way for new coders to pick up programming skills on the go.

CompileJava.net

Another free online Java compiler, CompileJava.net is simple but gets the job done. To use it, just paste your Java code into the editor on the left side of the page and click “Compile”. The compiled code will appear on the right side.

CompileJava.net supports:

• Java 8 and below

• Multiple files (just paste them separately into the editor)

• Console input

• Basic I/O

It’s a no-frills compiler without a lot of bells and whistles, but for quickly testing snippets of Java code, it works great. CompileJava.net can be accessed on both desktop and mobile, so you can code Java wherever you are.

Some other useful features of CompileJava.net include:

• Shareable links - You can share a link to any code you compile so others can see it.

• Save code - If you create an account (free), you can save code snippets to access later.-

• Download compiled code - Click the “Download” button to download the .class file of your compiled Java code.

While CompileJava.net may lack some of the advanced features of other Java compilers and IDEs like Eclipse or IntelliJ IDEA, its simplicity and portability make it a great option for on-the-go coding. If you just want to check if your Java skills are still up to par or test out a quick algorithm, CompileJava.net has got you covered.

Give CompileJava.net a try and code Java anywhere with this free, easy-to-use online compiler.

Conclusion

So now you've got a dozen free online Java compilers at your fingertips to code Java from anywhere. No more excuses that you can't work on your Java skills just because you're away from your main dev environment.

These cloud-based IDEs have you covered whether you want to hammer out some code on your phone during your commute, work on your side project from a coffee shop on your laptop, or even access a full IDE experience right from your browser.

With a variety of options for beginners and pros alike, you're sure to find an online Java compiler that suits your needs so you can start coding in Java today, wherever you are.