Replace Rule
A Practical Tool For API Testing
- Switch Hosts
- Redirect API Calls for Swift Testing
- Seamlessly Switch API Environments
- Target API Calls with Regex-Based Rules
- Maintain Streamlined Development Workflow
- Test New API Versions Without Code Changes
Your Development Companion
Gain comprehensive control over APIs for testing, switching environments and accelerating your development.
![fetch support - Requestly - Requestly](https://requestly.com/wp-content/uploads/2024/05/fetch-support.png)
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.
![replace URL - Requestly - Requestly](https://requestly.com/wp-content/uploads/2024/05/replace-URL-768x362.png)
![regex - Requestly - Requestly](https://requestly.com/wp-content/uploads/2024/05/regex-768x362.png)
Match URLs using Regex
GraphQL Support
![graphql support - Requestly - Requestly](https://requestly.com/wp-content/uploads/2024/04/graphql-support-9-768x375.png)
Trusted by 200k+ developers at →
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Popular Case Studies
Learn from real-world examples, See how others integrate Requestly into their workflows by exploring our case studies.
Related Blogs
Important Resources
Documentation
Specifications of Replace Rule
Tutorial
Step-by-step Guide & Video Tutorials
Use Cases
Learn Replace Rule is used across industry.
More HTTP Request & Response Manipulation Rules
These HTTP Rules designed for all your local development and testing needs.
Redirect Rule
Redirect a matching pattern to another URL.
Cancel Rule
Block URLs by specifying keywords or complete URL.
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.
Additional Features of Requestly
Mock Server
- Easy-to-use GUI, no command line.
- Mock Third Party APIs
- Faster than CLI-based tools.
- Various Import Options.
Session Book
- 1 Click Bug Report – Record screen with cursor, console logs, network logs & environment details.
- Debug 10x Faster – Use recorded screen, cusror movement, console logs, network logs & environment details to debug Faster.
For the developers, by the developers ❤️
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.
![](https://requestly.com/wp-content/uploads/2024/04/jose-browne-jpeg.webp)
![](https://requestly.com/wp-content/uploads/2024/04/Reddit-logo-jpeg.webp)
App works as expected! Ran into some small issues while creating the rules but the support team was able to help and overcome those.
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![](https://requestly.com/wp-content/uploads/2024/04/Vodafone-logo.png)
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.
![](https://requestly.com/wp-content/uploads/2024/04/marius-ludick-jpeg.webp)
![](https://requestly.com/wp-content/uploads/2024/04/Amazon-logo-jpeg.webp)
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.
![](https://requestly.com/wp-content/uploads/2024/04/natchapol-thongruang-jpeg.webp)
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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.
![](https://requestly.com/wp-content/uploads/2024/06/Srijan-Bhatnagar-LinkedIn-jpeg-e1717596108456.webp)
![](https://requestly.com/wp-content/uploads/2024/06/Atlassian-Logo.png)
Requestly is an incredibly useful tool for developers working on a large team with multiple staging envs, or numerous app endpoints for various APIs in a local environment. The Sessions feature is especially useful for documenting solutions or sharing with others since it captures the relevant network traffic, and screen recording enables others to easily reproduce. Requestly combines all the power of complicated tools like Charles Proxy and Postman in one app/chrome extension. I highly recommend giving it a try if you haven’t already–it will make your dev work so much easier. (Summarized)
![](https://requestly.com/wp-content/uploads/2024/07/Joel-Hawkins-Torres-jpeg.avif)
![](https://requestly.com/wp-content/uploads/2024/07/Autodesk-logo-jpeg.avif)
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.
![](https://requestly.com/wp-content/uploads/2023/10/carl.jpeg)
![](https://requestly.com/wp-content/uploads/2023/09/workday-logo.png)
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.
![](https://requestly.com/wp-content/uploads/2023/10/michael.jpeg)
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
![](https://requestly.com/wp-content/uploads/2023/10/machel.jpeg)
![](https://requestly.com/wp-content/uploads/2024/03/URBN-200x200-1.jpg)
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)
![](https://requestly.com/wp-content/uploads/2024/04/harsh-vats.png)
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