Open Source

Automate & change webpage's behaviour with JS & CSS

Customise any Webpage using Requestly’s Insert script Rule. Add Custom JavaScript (JS) or Styles (CSS) Remove/hide unwanted sections, add action buttons, add your own libraries to support your script, etc.

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Inject Custom Javascript

Inject custom JavaScript code into a webpage. This feature enables you to modify the behavior or appearance of a website by running your own scripts

Inject Custom CSS

Inject custom CSS styles into a webpage and override existing styles or add new styles to elements on a website

Multiple Scripts Support

Supports the execution of multiple scripts simultaneously on a webpage. This feature allows you to combine and apply multiple JavaScript or CSS injections to a website.

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Application and use cases

Here’s how you can use Requestly’s Insert Custom Scripts feature in your daily workflow

Inject custom JavaScript

You can use Requestly to inject custom JS on your specified URL. The possibilities for testing and modifications are endless with Requestly

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Inject custom CSS

You can let Requestly inject custom CSS on your specified URL, letting you test and verify your styles

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Load & Demo SaaS Apps

You can directly insert the installation code that you get for integration from the 3rd party app and try it on your website

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Intercept & Modify HTTP Requests

Boost Your Web Development: Advanced Tools for Seamless Debugging.

Redirect URL (Map Remote)

Redirect a request URL to another URL. e.g. Load local scripts in the production sites for faster debugging.

Override API Response

Test edge cases in your app by simulating API responses‍. Override XHR, fetch and AJAX responses.

Inject Custom Scripts

Add Custom JavaScript (JS) to Hide unwanted sections, add action buttons, inject your own libraries, etc.

Modify HTTP Headers

Add, Delete, Override Request & Response Headers. Can be used to remove X-Frame-Options, Content-Security-Policy, CORS Issues, etc.

Modify Query Params

Insert, Modify or Delete query parameters for URLs (or matching pattern). Burst cache for a request by assigning it a newer version.

Delay HTTP Requests

Simulate lag / delay to the response from specific URLs in a single click by using Requestly’s Delay Request Rule. No need to modify actual server.

More from Requestly

An open-source platform that speeds up your web development cycle 10X faster.

Session Recording

Data rich bug reporting with Network logs, Console logs, Session Video and environment details. Share it with your Engineering team for faster debugging.

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Mock API Server

Generate custom API responses without actually having a pre-built API or a backend server. Edit Content-Type, Status Code, Headers, and Response body easily on the Mock Server.

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Web-based API Client

A comprehensive and web-based tool for modifying and testing APIs. You can test the Mock APIs you’re creating here to fast track your development lifecycle.

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For the developers, by the developers ❤️

From Debug to Deploy: Developers Trust Requestly

“Requestly has changed how we work for the better. By employing it to rigorously test our staging code on external websites, we've experienced a turbo-boost in our testing speed!״

Andres Velasco

Tech Lead | Making Science

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

Michael Levinson

Co-Founder & CPO | Joyned

“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 amazing too and great to work in.״

Carl Hand

Senior Software Engineer | Workday

“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 pretty often, which is always nice. I can just use Requestly directly in Chrome״

Mike Mitchell

QA Engineer | Clayton Homes

Open Source

Automate & change webpage's behaviour with JS & CSS

Inject Custom Javascript

Inject Custom CSS

Multiple Scripts Support

Trusted by developers at

Application and use cases

Inject custom JavaScript

Inject custom CSS

Load & Demo SaaS Apps

Intercept & Modify HTTP Requests

Redirect URL (Map Remote)

Override API Response

Inject Custom Scripts

Modify HTTP Headers

Modify Query Params

Delay HTTP Requests

More from Requestly

Session Recording

Mock API Server

Web-based API Client

For the developers, by the developers ❤️

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