Requestly Chrome Extension is a developer tool that lets you intercept, modify, and mock HTTP requests directly in the browser. It’s ideal for testing, debugging, and simulating APIs—without backend changes. With a simple no-code interface, Requestly speeds up development and QA workflows. Works on all major browsers and has a desktop app for broader traffic control.
The Requestly Chrome Extension is one such tool—a powerful browser extension designed to intercept, modify, and mock web traffic in real time. Whether you’re a frontend developer, QA engineer, or product tester, Requestly simplifies your job by letting you control network behavior without needing backend changes or proxy configurations.
In this guide, we’ll explore the features, use cases, setup process, and benefits of using Requestly, ensuring you get a complete and accurate understanding of what it offers.
Requestly is a versatile developer tool available as a Chrome extension, browser extension for other major browsers, and a full-fledged desktop application. It enables developers to:
It’s particularly popular among frontend developers and testers who need quick, flexible control over network conditions or need to simulate incomplete or unstable APIs.
Unlike traditional debugging proxies or heavyweight tools like Charles Proxy or Fiddler, Requestly operates directly in the browser and is accessible even to those with minimal backend experience.
One of Requestly’s most powerful features is the ability to intercept and modify HTTP requests or responses on the fly. This allows you to:
These capabilities are crucial when you need to test features that depend on specific server behavior without having access to the backend.
Mock API responses directly in the browser without relying on a backend server or external mocking tools. You can create endpoints that return custom JSON, simulate latency, or mimic different HTTP statuses.
This is particularly useful when:
Redirect JavaScript or CSS files from production to local versions, reroute API calls to staging servers, or swap endpoints during testing. This feature is great for A/B testing, hotfixes, or working in microservices environments.
Requestly lets you inject JavaScript and CSS into any webpage. Use this to:
Simulate slow or failed network calls by delaying or blocking requests. This is essential for testing app behavior under poor connectivity, error states, or when an external service is down.
The Requestly Session Recorder captures browser sessions with console logs, network traffic, and environment details. It’s a helpful tool for reproducing bugs, collaborating with QA teams, or attaching session data to issue reports.
Requestly is available on a wide range of platforms:
There is also a Requestly Desktop App, which allows you to intercept and modify traffic from mobile devices, other browsers, or desktop apps—useful for more advanced testing scenarios.
You can download the desktop version here.
Go to the Chrome Web Store Requestly page and click “Add to Chrome”.
Click the Requestly icon in your browser toolbar. You’ll be taken to the Requestly dashboard, where you can start creating rules.
To mock an API:
Your app will now receive the mocked response instead of the real one.
Other rule types include:
Each rule is easy to configure with a guided UI, making it accessible even for junior developers.
Requestly shines in scenarios where traditional backend coordination is either slow or unavailable. Here are some common use cases:
Develop UIs independently by mocking backend responses with JSON data. This is ideal for agile teams working in parallel tracks.
Use redirect rules to reroute script calls or block problematic third-party SDKs to isolate bugs.
Modify request headers to simulate different authentication tokens or bypass CORS errors during local development.
Test how your app handles failed or slow API calls by throttling or blocking requests.
QA engineers can use preconfigured rules to test different API states without needing staging environments.
| Feature | Requestly | Postman | Mock Service Worker |
|---|---|---|---|
| In-browser rule execution | ✅ | ❌ | ❌ |
| Real-time network editing | ✅ | ❌ | ✅ (setup required) |
| Mock APIs | ✅ | ✅ | ✅ |
| Desktop + Mobile Support | ✅ (via desktop) | ❌ | ❌ |
| Visual UI for Rules | ✅ | ❌ (API-focused) | ❌ (code-based) |
If you need live modification and in-browser simulation, Requestly is the most user-friendly option.
Requestly offers a free version with essential features and a premium plan starting at approximately $8/month, which includes:
You can also opt for a team plan if you need shared workspaces and version-controlled rule sets for your development team.
More details available on Requestly Pricing.
Yes. Requestly is:
It does not collect or share your request data, and permissions are clearly listed during installation. With an active developer community and regular updates, Requestly is a trusted choice among professionals.
Requestly Chrome Extension is a must-have tool for modern web developers. It reduces dependency on backend teams, enhances testing flexibility, and improves debugging efficiency—all from within your browser.
Whether you’re building features before APIs are ready, reproducing bugs, or preparing for product demos, Requestly streamlines your workflow like no other browser-based tool. Its ease of use, cross-platform availability, and advanced features—especially with the desktop app—make Requestly one of the most robust and reliable API mocking and request modification tools on the market today.
