Inject Javascript or CSS on any webpage

4.8 ⭐ 1,200+ Ratings, 200,000+ users

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Requestly works on Desktop only

Requestly is a web proxy that requires a desktop and desktop browser.
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Trusted by 200k+ developers at →

Your Development Companion

Inject scripts easily to control API responses, making it simpler to test edge cases and speed up frontend development.

1. Inject Custom Js and CSS on any webpage

Add custom JavaScript and CSS snippets to any webpage without altering the original source code. This capability enables you to test new features, debug issues, or personalize content efficiently and seamlessly.

2. Run Local Scripts on Production

Debug and test changes directly on your production environment using local JavaScript files, ensuring the live user experience remains unaffected.

3. 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, enhancing functionality and customization.

4. Privacy, Security & Compliance

Requestly is enterprise-ready software that offers features like SSO, User Access Management, SLAs, SOC-II compliance, Reporting and analytics, and Role-based access control.

5. 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.

More HTTP Request & Response Manipulation Rules

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

Replace String

Replace part of URL like hostname, query values.

Modify Headers

Modify HTTP request & response headers.

Query Params

Add or Remove Query Parameters

Modify Response

Intercept, Modify & Mock API Responses in Real-Time

Delay Network

Simulate delay in response of API calls.

Modify Request Body

Modify body of POST requests.

Additional Features of Requestly

for frontend & QA teams

Mock Server

  • Easy-to-use GUI, no command line.
  • Mock Third Party APIs
  • Faster than CLI-based tools.
  • Various Import Options.
Read More

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.
Read More

API Client

  • Simple in-browser API Client
  • Test Your APIs
  • Test API Overrides
Read More

For the developers, by the developers ❤️

From Debug to Deploy: Developers Trust Requestly

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 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)

Joél Hawkins Torres
Senior Software Engineer at Autodesk

Modifying requests and/or responses is the killer feature area for me. Redirect JS in prod, generate mocks, modify headers, map local, map remote, SessionReplay, Load a local JS bundle, override scripts, etc. etc. etc. – TOTALLY worth it and very useful.

Jeff Chasin
Senior Evangelist at Adobe

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 at Making Science

Great tool! I use the tool to easily inject the script of our app onto customer websites to use during sales demos so I can show Fullview running on their sites

Daniel Bakh
CEO & Co-Founder at Fullview

Requestly has been a great asset for instantly creating client demos. I love their script injection feature which allows me to inject our code into any website and really impress our clients as they see our product on their website during demos :). It’s probably one of the best developer extensions out there. Great job Sachin and the team! 👏👏

Preet Raj
Co-founder & CTO at Bakstage.AI

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

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