Java programming language is one of the most versatile programming languages available. It offers a variety of features and tools to work upon. One of such tools is a debugging tool, which is one of the most important things required while coding.

Whether you are a beginner developer or working on java for decades, debugging tools will be a primary requirement of both. There are some exceptional Java debugging tools available to use. Each of them offers some unique and useful features to improve the productivity of Java developers. 

We will be discussing some best java debugging tools you should start using in 2021. These debugging tool either make or break the application debugging process, so you must go with the best option available as per your requirements. Most of these tools will be useful for identifying, diagnosing, and fixing errors in both development and production environments.

IDEs as Java debugging tools

Integrated Development Environments (IDEs) are usually used for debugging java applications. Although they are primarily used for development now all popular IDEs come equipped with the all debugging tools required for a smooth debugging process. They provide a suitable method of easily debugging your applications while helping streamline the development process by configuring the project and remembering all the APIs that are inherent in coding.

We will be mostly discussing different IDEs and their debugging features. While many IDEs are offering debugging tools, NetBeans, Eclipse, and IntelliJ, from JetBrains, are commonly used as java debugging tools. What differentiates IDEs are that some applications come with very basic toolsets, whereas others come with more advanced ones, allowing for additional debugging features, such as inline variable views and expression evaluation.

1. Java Discovery Protocol (JDP)

First on the list is a Java debugger called JDP (Java Discovery Protocol), It is a simple command-line java debugging tool provided by Oracle. Lacking even a simple graphical user interface, it is a complex and relatively difficult tool to use.

If you are restricted from using any external java debugging tools, you can go with it. It is the equivalent of the GNU Debugger for the Java Virtual Machine. You would probably already have it on your system as it comes with the Java SE Development Kit. You can start the debugger with the JDP command and you can see the list of commands using the help command.

A positive point of this debugger is that you can easily use it on the same box where you are running Java Virtual Machine (JVM). It means you won’t be needing to deal with any complexities of connecting any external service.

A command-line debugger is not the best option for every java developer because of its complexity. Despite that, its portability is something that cannot be undermined. You can easily set it up on a server without too much hassle. This makes JPD a more suitable debugging tool for the production environment.

2. NetBeans

NetBeans is one of the most popular and widely used open-source Java IDEs. It is also one of the best java debugging tools due to an extensive list of debugging features that come built into the platform. NetBeans can be installed on Linux, Windows, macOS, and Solaris. It provides you with a very handy feature of Visual Debugger for debugging visual elements of your Java GUI applications. With the Visual Debugger, you can also add listeners to GUI actions, view component properties and the hierarchy of components.

With the built-in NetBeans Profiler tool, you can monitor memory usage, CPU performance, thread states, and other characteristics of your Java application. The NetBeans debugger also provides some small yet useful features like breakpoints, run into methods, add field watches, monitor execution, and take snapshots during a debug session.

3. Rookout

Rookout is a great option among Java debugging tools options that can be used in development as well as production. It provides robust debugging features across various environments, including both containers as well as serverless.

The highlighting feature by Rookout is that it goes beyond the standard java debugging tools features by offering options for collecting and pipelining crucial data. This allows java developers to identify software execution issues and resolve them without the need to rewriting code, redeploying it or restarting the application. It eliminates the lengthy, complicated, and resource-intensive process of data exploration and bugs finding process.

4. Eclipse

Eclipse is another renowned open-source IDE with built-in Java debugging tools. Eclipse is considered one of the most robust cross-platform IDEs for developing modern java applications. It offers all the standard debugging functionalities along with some other specific debugging tools for java such as the option to set breakpoints, perform step execution, inspect variables and values, suspend and resume threads. It also facilitates remote debugging, making it among well-rounded Java debugging tools.

One of the highlighted debugging features by Eclipse is the Debug Perspective. It shows the relevant debugging information side by side with your line of code, such as variables, breakpoints, threads making it very convenient for developers to understand the flow of data in their code.

5. IntelliJ IDEA

IntelliJ IDEA is another well-known Java IDE that features a powerful debugger. Developed by JetBrains, IntelliJ IDEA is designed to primarily improve the workflow and productivity of Java development teams.

IntelliJ IDEA offers both an open-source version and a paid commercial version. It is mainly a Java IDE specifically used for android development in java, but it can also be used with other programming languages such as Groovy, Kotlin, and Scala. The commercial version supports many JVM and non-JVM frameworks too, like Spring, Java EE, Play, Grails, GWT, and Vaadin. It allows Java developers to easily debug code as well as multi-threaded Java applications.

IntelliJ offers debugging features like, you can set breakpoints, step through your code, evaluate expressions, inspect variables, and perform a range of other debugging features. It allows very easier detection of unexpected flows and states, deadlocks, livelocks, in the code.

It can also be used to debug Java applications remotely. IntelliJ IDEA also offers Inline debugging It displays the values of variables right next to the line within the code, where they were used. Whenever you would change the value of the variable, the inline debugger will highlight it with a different colour. So, to check the values, there would be no need to move to the Debug window or hover over each variable.

6. JDeveloper

JDeveloper is a freeware IDE by Oracle. It addresses every step of the application development lifecycle, from coding to designing, profiling, debugging, optimization, and deployment but it comes packed with some great debugging tools for java.

When debugging with JDeveloper, 

  • you can set breakpoints and watchpoints in your code, 
  • you can analyse the call stack,
  • It offers inspection and manipulation of variables,
  • Investigation of step-by-step code execution.

It is easy tools for detecting, diagnosing and resolving issues in your Java applications very accurately.

7. Raygun Crash Reporting tools

One of the most difficult things while debugging is that you can not always know which errors the users are experiencing or how they can be resolved unless you extensively analyze the error and its output. Raygun Error Monitoring comes with features you will be needing to identify errors and crashes that happened in production and even in later parts of the development cycle.

Raygun Crash Reporting allows you to send all the exceptions from desktop and console Java apps to your Raygun dashboard. It helps in debugging by showing a detailed diagnosis for each error that occurred. Raygun can also process any object that is inherited from the Throwable class. Advanced features like Breadcrumbs, Filters, and Custom Tags make the debugging process easier and convenient for developers.

It has a very easy and straight forward installation process. The installation and configuration do not take more than a few minutes. 

8. Visual Studio Code

You do not always require to use an IDE for debugging Java applications. Visual Studio Code, the cross-platform source code editor by Microsoft also makes Java debugging possible using a simple Debugger for Java extension.

If you use already using Visual Studio Code for development and also need a lightweight and easy to use java debugging tool for debugging your applications then Visual Studio Code can be a considerable choice. Despite all the advanced debugging features offered by IDE’s debuggers, it offers adequate features for a quick debugging session for your java application.

the Java debugger extension in visual studio is based on Java Debug Server which extends another Visual Studio Code extension called Language Support for Java by Red Hat.

Visual Studio Code debugger offers the following debugging features:

  • It performs local and remote debugging.
  • You can set up conditional breakpoints and log points.
  • It offers to step through the source code
  • You can Inspect and watch variables
  • Offers to View call stacks
  • You can debug multiple threads.
  • expressions can be evaluated
  • Use can also use hot code replacement

Visual Studio debugger extension comes with a series of configuration options that you can choose from as per your requirements.

Which of the Java debugging tools would be best for your application?

Debugging in Java has become very straight forward now. Using any of these java debugging tools will streamline your debugging process and makes it much quicker, you can easily debug your application and view the data alongside the code that has caused the error, and view data changes as the program progresses. 

Although each use-case is different, evaluating your requirements and needs will help you in choosing the right tool for your work. 

9. NerdVision

NerdVision, a debugging tool by Intergral GmbH  is among the few modern debugging tools for java that helps programmers reduce the time spent in debugging by not having to redeploy the application to enable debugging or logging. It is a non-intrusive collaborative debugger that enabling developers to set breakpoints and add watches for debugging without the need for stopping the execution of the application. It also offers some other great features like Quickly switch between multiple workspaces and Integration options for Git-based projects. Along with java it also supports debugging for Nodejs, python, .net etc.

Are these java debugging tools good enough?

While the tools, processes, and methods of program development have transformed, the debugging process itself has not evolved that much. In most modern applications, we can see the use of distributed systems, microservices, and a growing number of serverless deployments.

Traditional debugging tools have now started struggling with these new environments due to complex and virtualized networks, restricted resource allocations, and multiple deployments at once. The rapid increase in complexity has greatly restricted these debugging tools for instance, how can you debug an application using an IDE when more than 20 instances are running across a distributed environment? It cannot be done.

There are new debugging tools emerging that can be the solution to these problems. Debugging tools like NerdVision and other new java debugging tools are also in development that can be used with modern technologies.

See Also: Top 10 Best Java Profilers Of 2021


To wrap things up, the best among these java debugging tools would be a subjective choice. It would fully depend on your use case and preferences; if you are debugging in an isolated environment, then a tool like Java Discovery Protocol (JDP) would suit you best, even though it requires a high skill level for debugging in the command line but it also delivers some good set of tools. If you are debugging an application locally, then you can go with any of these full IDEs.

However, if you are working on debugging distributed systems or using automated tools then a modern debugging tool like NerdVision is should be your choice. Although it can also be used for both the distributed systems and your isolated and local applications if you wish to try it out.


Shaharyar Lalani is a developer with a strong interest in business analysis, project management, and UX design. He writes and teaches extensively on themes current in the world of web and app development, especially in Java technology.

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