Top 6 online Java compilers for students

java compilers
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What makes a great Java compiler? In this article, Jean-Pal will go over six of the most popular online compilers and IDEs for Java that are most suitable for students.

Do you want to get started on Java? Are you an impatient programmer who hate installing any software on your computer? Until recently, you didn’t have many options.

You had to download a Java compiler or download and install an IDE like Eclipse. Options for compilers were limited.

Today, there are a number of online compilers and IDEs. These offer significant advantages over the desktop options.

  • Easy to set up – No downloads; No installs; No PATH variables.
  • Quickstart – many just open in seconds, unlike Eclipse that takes 1 minute to start.
  • Easy sharing – Teachers share the code with students, students share their assignments, post any questions to Stack Overflow. It’s super easy! Just copy the link and paste it.

Some online compilers like Codiva and JDoodle are suitable for learning programming and practicing interview problems. These are simple and easy to get started. Features optimized for this specific use case.

On the other end of the spectrum, there are online IDEs like Codenvy and Cloud 9. These provide complete development environment, that professionals can use. Many startups use it to provide a consistent preconfigured development environment that all their developers can use, with no maintenance.

SEE MORE: Translate Go into JavaScript with the all-new Joy compiler

In this article, we will review Online compilers and IDEs suitable for students, and for professionals practicing interview programs when switching jobs. In no particular order:

1. Codiva is our top pick for online Java compiler. It is new to this game, but it has some cool features.

The single biggest feature of Codiva is, it compiles as you type, parses the compilation errors and shows it in editor. By the time, you complete typing, you get the compilation results.

It also has a pretty good autocompletion. These two features will save you a lot of time when coding.

Codiva supports multiple files and packages, and can have custom file names. You can also run interactive programs. So most of the topics for beginners learning Java and Algorithms course can be completed with Codiva itself.

Codiva is also the only IDE that works reasonably well on mobile.

Some disadvantages of Codiva are, it supports only Java, C and C++, doesn’t offer UI themes, or different compiler settings. Codiva supports Java 9, but doesn’t support Java 9 Modules. Of course no other online compilers support Java 9 modules either.

java compilers

Autocompletion and error handling in Codiva

Overall, it is a great tool to code in Java. Try the online Java compiler here.

SEE MORE: One year after Java 8’s release, IDEs and compilers are not fully ready yet

2. JDoodle

JDoodle is a popular online compiler for Java. It started for Java, but now supports almost 70 languages. JDoodle allows only a single file but you don’t have to specify any filename. It finds it by parsing the file contents.

JDoodle has excellent terminal support for running interactive programs. By default, the programs are run in non-interactive mode with 10s limit. But you can switch to interactive mode if required for each project.

If you are a kind of a person who learns a lot of programming languages, or switches between multiple languages often, JDoodle would be a great choice.

For Java, the major disadvantage for JDoodle compared to Codiva is, you have to manually click compile every time you finish the code. Then read through the error messages, find the line number, and go back to the editor. You will find it annoying if you have used a desktop IDE or coded with Codiva before.

The second disadvantage is, it only supports one file. If you are using it for programming course, then the concept of packages, encapsulation, etc cannot be taught.

Despite these drawbacks, JDoodle is a great site. It is popular for a reason.

java compilers

Try JDoodle here.

SEE MORE: Java 10: These APIs are as good as gone

3. Rextester

Rextester started as a Regular Expression Tester, later grew to be an online IDE. It supports around 30 languages including Java, but it is more popular among C# users.

Rextester allows switching between multiple editor widgets to suit your preference.

It has one of the best live collaboration support. Just share the URL, start typing. Multiple users can edit at the same time, and so far, I haven’t seen a glitch.

Rextester supports only a single file, and the class should be named Rextester. Also, the class should NOT be made public. At the time of writing this, it supports only Java 8.

java compilers

Try Rextester if you want to live collaboration

SEE MORE: Maven on Java 9 – Six things you need to know

4. OnlineGDB

Online GDB is the online tool that supports a built-in debugger. If you write some complex program, and have to debug in case of an error, the debugger will come in handy.

You can set a breakpoint, and when running the code, it will stop at that line, and progress through the code step by step, and see the intermediate variable values.

It also has a built-in code-formatter, that formats the code automatically to a decently formatted code, but you cannot define your preferred code style though.

It supports only Java 8. The compilation is a bit slow, but it is still worth trying.

java compilers

SEE MORE: This tool will come in handy if you’re a Java developer who needs to write web front-end from scratch

5. Browxy

Browxy used to be popular but started to lag behind. It supports multiple files. At present only Java 8.

Browxy is the only online compiler that has almost no restrictions. You can even send network requests to external URLs.

This will be super useful if you want to practice calling API calls. It also supports Applets, but no one uses Applets anyway.

Browxy compiles and runs fast, we get the response within a fraction of a second.

java compilers

SEE MORE: FastR: A new R virtual machine written in Java

6. IDEOne

Ideone is one of the first online compilers that are still around. So it deserves an honorable mention.

It supports around 60+ languages. Ideone hasn’t been updated to support Java 9. IDEOne provides an API for compilation as a service, that you can use to build your own online IDE to be used on your website.

java compilers

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Today, every tool that you had previously used is available in the cloud. IDEs although heavily used by the developers, had been a bit hard to develop for the cloud, but it is happening.

Unlike the desktop world where each IDE tries to do everything and become bloated, I predict the online IDE market will be fragmented and targeted for niche use cases.

There will be IDEs separately for students and separately for professionals. Because, each of them is going to be one link away, so why bloat the site?



Jean-Pal is a software developer and a freelance ghost writer. He specializes in tech articles.

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