Integrating with APIs can be challenging. Each with its own documentation format, SDK patterns, and authentication quirks. Once you get the integration up and running, the harder step is testing and debugging any problems. This part can be exploratory—before you finish building—or as part of problem resolution.
While you can certainly debug within your codebase, by testing methods and reviewing logs, it can be beneficial to isolate the API calls by using one of the many API testing tools available.
Rather than list the pros and cons of each, let's focus on what makes each tool unique and worth trying.
Cost: Free + Paid Plans
Postman is an institution in this space. It's been around for years, and went from a small app that made API calls into the full ecosystem that it is today. While Postman's primary use case is building and managing your own APIs, their emphasis on encouraging third-parties to publish collections has made it a great tool for exploring and debugging web services. These collections are what make Postman a fantastic tool for debugging external API calls.
Some providers, like Zendesk, link directly to their Postman collections in their documentation. Others can be found on Postman's Explore page, and then opened within the Postman app. Once installed, you can explore endpoints and resources with minimal setup.
Hoppscotch started as a faster, browser-first alternative to Postman, called Postwoman. It has since been rebranded and continues to add features. Its main benefits are speed and availability. It is also open source, and can even run as a browser extension or progressive web app (PWA).
Cost: Free Trial, then $49.99
Moving on to platform-specific applications, Paw is a paid Mac application for interacting with APIs. Like many of the others, it's core focus is on providing a tool to build, test, and document your own APIs. Perhaps Paw's greatest selling point is the UI. Compared to many of the other application's on this list, it really feels like quality Mac-first software. It also offers Team functionality, and an interesting feature called Pawprint that lets you share request/response pairs via a URL, even if the receiver doesn't use Paw.
Cost: Free + Paid plans.
Insomnia is another API client that lets you design, debug, and test APIs. Unlike some of the other "all-inclusive" applications, Insomnia splits the API designer functionality into a seperate app. This makes the UI much more approachable, and makes it easier to quickly try out a new request without excess setup and configuration.
One additional tool that you can find in their documentation is a CLI version called Inso. It allows you to use the functionality from both their core Insomnia client as well as the designer app, right from the command line, and even from within CI/CD environments.
Cost: Free plan + additional Paid plans
While the rest of the applications in this list are centered around allowing you to directly interface with APIs, Fiddler takes a different approach. It is more of a general purpose web debugging tool. It acts as a proxy to capture local requests between your device and the internet. This means you can run your application locally, and inspect any outgoing requests and incoming responses from the Fiddler application.
This approach can be useful for live-debugging, but it also allows you to mock requests and responses that match specific rules. Combined with features around creating collections of requests and responses, and the ability to collaborate with a team, this approach could really help debugging more complex API problems.
Choosing the right tool, not just for the task, but also for your workflow can be a challenge. Fortunately, all of the options we've looked at here are free or offer free trials to get you started. They can all help make exploring and debugging APIs easier. When it comes to debugging API problems in your live site, Bearer has a solution. We can detect problems automatically, help you track API performance, and you can enable detailed rules to watch for edge cases. Check out Bearer today, and take control of your API usage.