ModHeader is a Chrome extension designed for modifying HTTP request and response headers. It works well for basic use cases but comes with limitations like feature caps, ads, and privacy concerns.
Requestly is a free and open-source tool that lets you modify HTTP headers without limits. It also includes features for debugging, team collaboration, and gives you full control over your rules
What ModHeader Can Do ?
ModHeader allows users to modify HTTP request and response headers directly in the browser. Here’s what it can do:
Beyond interception
Not just a HTTP interceptor tool
Developers can now debug errors without juggling between their development environment and bug tracker.
Modify Headers
Add, remove, or override any HTTP header like Authorization, User-Agent, Cookie, CORS headers, and custom headers. 
Import & Export
Easily Import & Export your configurations or share them across devices and teams using JSON import/export functionality. 
Rule Profiles
Group multiple header modification rules into a single profile and toggle them on or off as a set for different workflows or environments. 
Common Problems Users Report About ModHeader
From analyzing their recent Chrome Store reviews, here’s what comes up over and over:
Powerful toolkit
Why ModHeader users are switching to Requestly
Intrusive Ads ModHeader displays ads that can be distracting and annoying, especially when you’re trying to focus on your work. Privacy Concerns ModHeader has access to your browsing data, which raises concerns about your privacy and security. Performance Problems ModHeader can slow down your browser and affect the performance of web pages, especially when you have multiple rules enabled. Limited Free Plan ModHeader’s free plan has limited features and rules, which may not be sufficient for your needs.
ModHeader Plans
ModHeader has three plans, two free and one paid, but in most cases, users end up choosing between the two free options:
Free ( Ad-sponsored )
The default plan for most users. It gives access to core features, but includes in-app ads that can be distracting.
Unlimited rules & profiles
Includes ModResponse Pro
Ad-free experience
Free ( With Limits )
Designed for users who want an ad-free experience, but with tight usage limits. It’s ad-free, but comes with serious restrictions.
Up to 10 rules & 3 profiles
Share profiles publicly or with a few individuals
Ad-free experience
Alternative Solutions
If you’re frustrated with ModHeader’s issues, you’re not alone. The good news is: you have options.
Here’s what many developers explore next:
Requestly
Requestly offers unlimited free header modifications, powerful collaboration features for teams, and enterprise-grade security.
Header Editor Basic header editing, but now outdated. With Manifest V2 deprecating, it’s losing long-term support and may break in future updates. 
Modify Header Value A small, lightweight tool with few users. Covers basic needs but lacks team features, support, and advanced capabilities. 
Why Requestly?
Requestly is one of the most trusted and widely used tools for HTTP header modification — and it’s built with developers in mind.
Unlike other tools that limit functionality or compromise on privacy, Requestly offers unlimited header modifications for free. Whether you’re tweaking Authorization headers, customizing CORS settings, or managing cookies and redirects, Requestly gives you the power and flexibility to handle it all — with zero ads, no performance drag, and full transparency
Requestly — A Better Alternative to ModHeader
No ads. No limits. No compromises.
Powerful toolkit
Requestly: A better alternative
Free Header Modification Requestly lets you create and manage as many header modification rules as you need, completely free. Open Source Requestly is a powerful open-source tool, giving you full transparency, flexibility, and control over how it works. Privacy Focused Requestly respects your privacy and does not collect any personal data or browsing history. Ad-Free Usage Requestly is completely ad-free, so you can focus on your work without any distractions.
Don’t Just Take Our Word for It
Thousands of developers trust Requestly for HTTP header modifications, with top ratings on the Chrome Web Store for speed, flexibility, and support.
★★★★★ on Chrome store
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 
★★★★★ on Chrome store
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 
★★★★★ on Chrome store
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 
★★★★★ on Chrome store
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 
★★★★★ on Chrome store
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 
★★★★★ on Chrome store
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 
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 
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 
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 
Migrate from Modheader to Requestly in a single click
Import your Modheader configurations to Requestly with 1-click and enhance your web development experience. Click the button below to start a the process.
Frequently Asked Questions
What is Requestly and how is it different from ModHeader ?
Requestly is a powerful HTTP interception and mocking tool that lets you intercept, record, and mock HTTP requests on the fly. While ModHeader is limited to modifying headers, Requestly goes much further, allowing you to redirect URLs, override API responses, inject scripts, block requests, and collaborate with your team using a modern UI.
Is Requestly more secure than ModHeader?
Yes. Requestly is designed with enterprise-grade security in mind, including features like role-based access control (RBAC), single sign-on (SSO), and SOC 2 compliance. ModHeader is a basic browser extension with minimal security features and limited control over your data.
Is Requestly open-source
Feel free to check out the GitHub repo
Is Requestly free to use ?
Yes. Requestly offers a Free plan with essential features like unlimited header rules and standard HTTP modifications, perfect for getting started.
Does Requestly offer an enterprise plan?
Yes. Requestly offers an Enterprise Plan built for larger teams and organizations that need full control and compliance. It includes unlimited usage, API access, SSO & SAML, GDPR and SOC 2 compliance, user access management, SLAs for support and uptime, invoice-based billing, and priority support via Slack Connect, Email, and Chat.
Is Requestly free for students?
Yes! Requestly is free for students, enjoy access to powerful tools and features with no cost.
Why are my response header modifications not visible in the browser’s dev tools?
Response header modifications done by Requestly are not always visible in the browser’s dev tools, but rest assured, they are being applied correctly. You can verify it by inspecting the network traffic through Requestly itself.
Why Aren’t My Requestly Rules Working?
How do I modify headers using Requestly?
Learn more about modify header rule
Can I apply header modifications to specific HTTP methods (GET, POST, etc.)?
Yes, you can apply header modifications to specific HTTP methods by specifying the method condition within the rule settings. This ensures that headers are modified only for requests of certain types. For a detailed guide,.
Can I import my ModHeader settings directly into Requestly?
Yes, Requestly supports one-click migration to seamlessly import your ModHeader settings, making the transition quick and easy.