Best Free Debugging Tools for API Development

The debugging process is an essential step you need to take in the development of all kinds of software. By doing it regularly, you will ensure that your code will work perfectly. If you fail to do so, there is a risk of your code getting messy, which makes finding the problem a really hard task.

Just ask a developer if debugging tools are his best friends and we guarantee that his answer is going to be “yes.” The debugging process has four steps, which can apply to any kind of programming. In general, the process looks something like this:

  • Finding a problem
  • Isolating a problem
  • Correcting the code
  • Testing of the code you corrected

And you need to go through these four steps time and time again. Developing a piece of software is a time-consuming process after all. That’s why you need to automate this one, and processes like online API documentation as much as possible.

Of course, there are many different tools that can help you with this. In order to help you save up some time, we are going to talk about debugging tools for API development. There are free and paid tools out there, but we recognize that most people work on a tight budget.

Therefore, here we have the best free debugging tools available on the market today…


When you share the HTTP traces with the rest of your team, you want to enable a replay scenario in order to avoid repeating those requests again and again. This saves a lot of memory, time, and eventually money. To avoid repeating this task, you should use the ApiRequest.IO. This is Chrome extension will capture the AJAX calls and store them in a cloud service. By doing this, you will create a 30-day-long workspace that can be shared by you and your coworkers.


The PostMan is a dedicated HTTP client that makes sending the API requests easier than ever. No matter how much experience you have, you’ll be able to use this tool. That’s because of its beautifully-designed graphic user interface. But even if you’re a veteran developer, you’ll still find some use for it. It gives you access to your API call history, and if you find some errors, it allows you to make the calls again in a matter of minutes.

Apache Jmeter

This free tool is specifically used for performance testing.  Now, you need to realize that performance-testing tools for APIs are far and few between in today’s market, so you should get your hands on this one. Making a hosted service is hard on its own but without the proper testing tools, it will take you ages to finish it. There is another free testing tool we would like to mention and it is called These two tools work great in tandem and will satisfy most of your testing needs and wishes.

The Debugger

For example, if the API used in the application is an interface, and is connecting the backend with the frontend. It is good to know which side made the mistake when the problem is obvious and is interrupting the functionality of the app. By knowing which side made the mistake, it’s a lot easier to locate and correct it. This kind of problem is going to emerge in your web application mostly. In this case, you can use the debugger from your browser development tools. Most of the browsers we use every day have some kind of developer tools. And obviously, this means that they are free.


Now, this right here is the second HTTP client on this list. While it works very similarly to PostMan, there are certain differences between the two. For instance, this one is preferable for those developers who like the command line based tools. Needless to say, the cURL is pretty fast and will allow you to test your tools in far less time than it would take you usually. With this tool, you can build some scripts for deployment and the testing of your apps as well.

Charles Proxy

Charles proxy is a very useful tool. Since it`s not hosted on the internet, you need to install it on your local machine. You can route the traffic of your local machine through as an HTTP proxy. Also, by opening a port on your pc, you can configure your mobile phone traffic to go through the Charles Proxy. It is important to disable the proxy on your phone after you disconnect it from the pc. If you don`t do this, your mobile phone will not be able to connect to the internet, because all of its traffic will go through the proxy.

The Bottom Line

As we said in the beginning, debugging tools are crucial both in the development and the testing process. That’s why we covered both the important steps in the debugging process and the tools you need to go through these steps.

While all of the tools we looked at are useful in their own way, you probably won’t need them all. Our recommendation is to do some more research, see which ones you’ll need the most and then test them out. That’s probably the best thing in this situation.

We hope you enjoyed our writing and that you found our article helpful in some way. If you have anything to add – or if you have any additional questions – feel free to leave a comment in the comment section below.