APIs power almost every modern application, which is why there are so many tools available for the testing and development of APIs.
While most developers rely on complete applications, some useful Chrome extensions can optimize this process for developers.
Today, we will cover some of the best Chrome extensions for API development and testing in 2025.
Let's jump in.
If you're not aware, Chrome has been making changes that could lead to some extensions no longer being supported.
Manifest V2 is now Deprecated meaning Chrome is transitioning to Manifest V3 which restricts certain functionalities used by many existing extensions, especially ad blockers and privacy tools.
You can read more on this hackernews thread.
All of these extensions follow the latest guidelines (except the last one).
1. Requestly - free API testing and mocking tool.
Requestly is an open source frontend development platform that helps developers test and debug their apps faster without needing multiple deployment cycles.
The Chrome extension helps you to:
✅ Redirecting URLs and testing GraphQL APIs.
✅ Intercept and Modify HTTP Requests and Responses.
✅ Testing, Validating, Mocking API responses and many more.
This is how it looks.
They also provide the desktop app (windows, Linux, Apple Chip, Mac Intel Chip) if you want a native experience, where you get a lot of more options.
✅ API Client that helps in testing the API during development as well as during QA.
There is support for API collections, variables in environments, local log of API Requests for history. You can also Import and export API contracts and collections from various sources, including cURL, OpenAPI, Postman and more. I've covered complete details on the API client in this blog.
✅ You can also create cloud-based mocks using the mock server. Similarly, you can create local mocks using the Modify API Response rule, which lets you change the response status and body to test different situations.
✅ You can also monitor and record mobile/desktop app API traffic using Network Interceptor.
✅ You can record API traffic from the interceptor to create bulk API mocks in seconds, making it easy to mock an entire service quickly.
The Chrome extension has 200,000 users with a 4.3 rating (1.2k reviews).
2. Postman Interceptor - capture browser requests and sync with postman.
Many developers rely on Postman for API testing, but capturing browser requests can be tricky.
Postman Interceptor solves this by syncing cookies and headers from your browser to Postman, making it easier to debug APIs.
The Interceptor makes this process painless. Something that would have required a proxy earlier can now be achieved without any installation steps or extra configuration.
It has 700,000 users with a 4.3 rating (956 reviews).
3. Talend API Tester - visually interact with REST, SOAP and HTTP APIs.
Talend API Tester makes it easy to invoke, discover and test HTTP and REST APIs. It was previously known as Restlet Client.
This helps you to:
✅ Send requests and inspect responses.
Requests can be made dynamic by inserting variables. Security and authentication are fully supported, as well as hypermedia and HTML forms. You can visualize, prettify and inspect HTTP responses.
✅ You can perform many sorts of API response tests. Such as using assertions to validate values of headers, parts of the body or response time.
✅ Validate responses with assertions (status, headers, XML and JSON body, response time...).
✅ Easily import your Postman Collections, Swagger / OAS / OpenAPI and HAR (HTTP Archive).
It has 600,000 users with a 4.8 rating (4.2k reviews).
4. Boomerang - SOAP & REST Client.
Boomerang is an API testing tool for both REST APIs and SOAP services, meaning that you can test both from one single application.
You can also export and import data, and the extension keeps a history of your sent requests so that you can easily refer back. You can also create dynamic requests using variables and scripting.
It uses local data storage without cloud dependencies.
It has 100,000 users with a 4.6 rating (1k reviews).
5. ModResponse - mock and replay API.
With ModResponse, you can modify, stub and replay HTTP responses. It requires no extra proxy or code change to be made, so you can quickly test different scenarios and debug edge cases.
There are also advanced filtering options and you can simulate network errors.
Let's imagine you have API requests that are taking a long time to finish, and every time you make a small UI tweak you need to wait more than 10 seconds for the API request to finish to visualize your change.
Using replay response, you can record and replay the slow API request. That way, you will only need to wait on the slow API request once. All subsequent requests are to be served from the cached response within a few milliseconds.
It has 10,000 users with a 4.6 rating (23 reviews).
6. LambdaTest - automated cross browser testing.
While this is not directly related to API testing but it's worth checking out.
You would have seen a site looks perfect on your machine, but then it has a broken layout on someone else phone. LambdaTest eliminates that guesswork.
You can do automated cross browser testing on 2000+ real browsers and operating systems. You also don't need to repeat the process of selecting real-time browsers every time. Just add your favorite configurations and it needs a single click from your browser tab.
You can generate screenshots, schedule screenshots, conduct geolocation tests and much more.
It has 7,000 users with a 4.6 rating (19 reviews).
7. JSON Viewer Pro - beautifies and organizes JSON data.
A big minified JSON response is really hard to debug. This extension automatically formats and syntax highlights JSON data in your browser, making it much easier to read and understand.
You can import JSON data, access JSON in your console, get depth traversing of JSON property using breadcrumbs and also copy the path (or value) of each endpoint. It gives two formatting options.
JSON (JavaScript Object Notation) is the most commonly used data format in APIs today which makes this very useful.
It has 200,000 users with a 4.7 rating (138 reviews).
8. Clear Cache - clears cache, cookies and site data in one click.
Clear Cache provides a quick and easy way to clear your browser's cache, cookies, images, files and other site data with a single click.
When you're developing web applications or testing API integrations, cached data can often lead to unexpected behavior or outdated results. Instead of digging through browser settings, this extension gives a convenient shortcut to make sure you are working with a clean slate.
You get fine-grained control over what gets cleared and it only clears data from the active tab, so it's really useful as a developer.
It has 1,000,000 users with a 4.5 rating (1.1k reviews).
9. Ghost Inspector - automated website tests.
Ghost Inspector is an automated browser testing service that allows you to run automated tests on your websites and web applications to check if they are functioning properly.
You can record them on your staging server and execute them through our API when your code changes, or record them on your live site and automatically run them at a set interval to continuously check for issues.
You can watch this demo video to understand the concept!
It has 10,000 users with a 4.2 rating (30 reviews).
10. Yet Another REST Client - test and debug REST APIs.
YARC (Yet Another REST Client) is a simple REST Client which can help you to develop, test and debug RESTful APIs.
You can:
✅ View all your previous requests and responses.
✅ Choose from a large range of existing request headers.
✅ View the request response in beautiful syntax highlighting (including JSON, XML, HTML and CSS).
✅ Save favorite requests (including headers, payload...) and re-use them with the click of a button.
It supports other methods (GET, POST, PUT, DELETE, PATCH, HEAD, OPTIONS) and you can also see how long each request took to complete.
Please note this extension may soon no longer be supported because it doesn't follow best practices for Chrome extensions.
It has 60,000 users with a 4.4 rating (138 reviews).
Check Yet Another REST Client 🔥
I was researching other extensions as well, so here are a couple of useful ones:
- Checkbot - SEO, web speed & security tester.
- vREST - REST API testing tool.
- Rest API Inspector - inspect all the REST API calls and download with extra details.
- User-Agent Switcher - quickly and easily switch between user-agent strings.
That’s all!
APIs are everywhere and having the right tools can make development and debugging way easier.
I hope you found something valuable, let me know if you know of any other useful extensions.
Have a great day! Until next time :)
| You can check my work at anmolbaranwal.com. Thank you for reading! 🥰 |
  
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Top comments (4)
Any suggestion for Socket.IO tester client? Have search for a long time.
I believe Postman supports that, so just go for it. Otherwise, check out Socket.IO Test Client.
This should do the job. Hope it helps!
Good one, Anmol. 🙌
Planning on giving Requestly a shot.
Thanks for reading, Shrijal! 🔥 As a honest opinion, I personally feel that Requestly is more powerful for teams than for solo developers.