Why I Switched to Requestly: The “Better” Open Source API Client

For years, Postman has been the standard tool for developers testing the APIs they build. It’s a reliable client for creating and sending requests. However, a common developer challenge extends beyond self-initiated API calls: the need to debug all the other network traffic happening on a machine, from browser activity to background processes.

Enter Requestly, a free, open-source tool that functions not only as a powerful Postman alternative but also offers features that are genuinely “mind-blowing.”

Takeaway 1: It’s Not Just an API Client — It’s a Full Network Interception Suite

This comprehensive interception capability is what elevates Requestly from a simple API client to an essential debugging utility. Its most powerful feature is its ability to act as a proxy server to intercept, inspect, and log network traffic from virtually any source on your machine. It can monitor traffic from:

• Sandboxed Browsers: Requestly can launch a new, sandboxed Google Chrome instance and automatically log every single network request that originates from it, allowing you to see exactly which API calls a web page is making.

• Terminal & cURL Commands: It can intercept traffic originating from the terminal, allowing you to see the full request and response details for commands like curl. The reviewer noted this was a novel feature: "This is something I... have seen first time."

• System-Wide Applications: For debugging complex dependency installations or background services, Requestly can configure a system-wide proxy to capture network traffic from any application on your computer. The source demonstrated this by intercepting the network calls made during a pnpm install command and from a running Node.js script.

• Mobile & Remote Devices: Users can intercept all network traffic from a mobile phone (Android or iPhone) by manually configuring the device’s Wi-Fi proxy settings to point to the Requestly desktop client.

This ability to intercept traffic from terminals, mobile devices, and system-wide processes is what transforms the tool from a simple API client into an essential, universal debugging utility.

It is a game changer for debugging…

Takeaway 2: You Can “Edit and Replay” Any Intercepted Request

Requestly allows for more than just passive observation; it lets you actively modify and resend any network request you’ve captured. This “Edit and Replay” feature dramatically accelerates the debugging process.

For instance, if an intercepted API call made from a web application has an error, such as a typo in the URL like example.com/xyz, you don't need to go back to the source code to fix it. Instead, you can directly edit the request within the Requestly client, correct the URL to example.com, and resend it immediately to see the successful response. This stands in stark contrast to the traditional workflow of finding the relevant line in the codebase, making a change, restarting a server, and re-triggering the entire user action just to test a small fix.

Takeaway 3: It Accelerates Workflow with Code Generation and AI-Powered Tests

Requestly includes several features designed to speed up common development tasks.

First, its “Get Client Code” feature can automatically generate the code snippet for any given request in a variety of languages and libraries. For example, it can produce a ready-to-use JavaScript axios snippet for a request you've built or intercepted, a capability described as a "very handy feature."

Second, it offers AI-powered test case generation. With a single click, Requestly can create basic tests for an API call, such as verifying the HTTP status code is 200 or confirming the request method is GET. Developers can also write more advanced tests; as the source notes, "you can of course add more test cases... in which you can also validate the body that the body should contain a userId field, a title, etc."

Takeaway 4: It’s Genuinely Free, Open-Source, and a “Better” Alternative

Requestly is a completely free and open-source project. It achieves this power without the bloat often associated with mature developer tools; the reviewer praised its “light weightness” as a key feature that first captured his attention. He also makes a strong assertion that calling it a mere “alternative” to Postman is insufficient to describe its value.

Actually, they should not call it a free and open source alternative. They should actually say it as free and open source better alternate to Postman. Now this makes more sense.

The project is available on GitHub, and the reviewer encourages developers to star the repository because “these kind of mind blowing projects… they deserve a star,” reinforcing its value to the open-source community.

Furthermore, it doesn’t lack core professional capabilities. Requestly includes support for multiple environments, request history, runtime variables, and the ability to import collections and specifications from Postman and OpenAPI, ensuring a smooth transition for experienced users.

Conclusion: The New Standard for Developer Debugging?

Requestly is more than a capable, minimalist API client; it’s an all-in-one, lightweight network debugging powerhouse that signals a shift in developer tooling towards integrated debugging suites. By providing developers with the tools to intercept, inspect, and modify traffic from any application, browser, or device, it addresses a much broader set of challenges than a traditional API client.

With such powerful, accessible interception tools now available, how can debugging workflows in your own projects be completely transformed?