Replace Rule

A Practical Tool For API Testing

4.8 ⭐ 1100+ Ratings, 200,000+ users

Your Development Companion

Gain comprehensive control over APIs for testing, switching environments and accelerating your development.

Supports APIs triggered as XHR or fetch

Gain control over API responses triggered by XHR/Fetch requests. As a result, you can effortlessly switch between development, staging, and production environments without touching your codebase, streamlining your development workflow.

Replace Multiple parts of a URL

With pinpoint accuracy, target and replace multiple URL components – hostname, path segments, query parameters, and more – for granular control over your requests.

Match URLs using Regex

Use regular expressions to achieve intricate URL pattern matching without the need for overly complex, indirect approaches. This grants you granular control over your URL replacements in a more streamlined manner.

GraphQL Support

Test Staging GraphQL APIs with Production frontend, making sure all the operations are working properly, ensuring a seamless user experience post-deployment.

Collaboration & 1-Click Sharing

Promote consistency and accelerate development by sharing Requestly rules within your team. Choose between shared workspaces for real-time collaboration or targeted sharing with individual members.

Trusted by 200k+ developers at →

Related Blogs

Important Resources

More HTTP Request & Response Manipulation Rules

These HTTP Rules designed for all your local development and testing needs.

Modify API Response

Modify response of any XHR/Fetch Request.

Modify Headers

Modify HTTP request & response headers.

Query Params

Add or Remove Query Parameters

Insert Script

Inject Custom JS & CSS on any website(s).

Delay Network

Simulate delay in response of API calls.

Modify Request Body

Modify body of POST requests.

Requestly Highlights

A comprehensive debugging suite with thoughtfully designed features for front-end developers.

For the developers, by the developers ❤️

From Debug to Deploy: Developers Trust Requestly

This is by far the best tool for managing request headers! Plus the developers are very active meaning you’ll get help if you’re ever stuck or need help solving a problem. I use it daily and couldn’t be happier.

Jose Browne
Senior Engineer at Reddit

App works as expected! Ran into some small issues while creating the rules but the support team was able to help and overcome those.

José Miguel Dias Fernandes
Development Lead at Vodafone

Requestly is user-friendly, brilliant and easy-to-use. I use it on an daily basis and it makes my work easier. After using other tools like Charles – Requestly is a nice new breath of air that I highly vouch for. Apart from the tool being amazing – the support from the Requestly team is phenomenal with them always going above and beyond for their clients.

Marius Ludick
Solutions Architect II at Amazon

Requestly is an amazing tool to get your development work less hassle. The product itself has evolved so much since day-1 and the company is really serious on helping their customer solves their problems. We had this nice session where they shared Requestly features and we were very impressed on its potential. A truly 5-star worthy.

Natchapol Thongruang
Senior Software Engineer at Agoda

Just loved the way Requestly saved several person hours for our dev team by allowing us to redirect and intercept requests. The simple yet efficient rules allowed us to seamlessly redirect requests from a single staging front-end server to local backend servers. This meant that our devs didn’t need to build or run the front-end server locally when focusing on backend tasks.

Srijan Bhatnagar
Senior Software Engineer at Atlassian

Requestly is awesome. I used to use Charles proxy in my day-to-day work but it always messed with my wifi. I haven’t had any issues with Requestly. Requestly’s UI is an amazing tool and great to work in.

Carl Hand
Senior Software Engineer at Workday

Requestly not just made it easier for us to develop, test & debug our code on our customer sites but also helped us do engaging product demos to our prospective clients.

Michael Levinson
Co-Founder & CPO at Joyned

I’m a big fan of Requestly, and use it on a daily basis as a QA Engineer. It removes the need to use Charles Proxy often, which is always nice. I can just use Requestly directly in Chrome

Mike Mitchell
QA Engineer at URBN

Awesome tool. I use it almost daily for my projects to modify request body, headers, etc. Would recommend it to every frontend developer out there. Thank me later 🙂 (Case Study)

Harsh Vats
Frontend Engineer at PingSafe