Requestly ➜ Simple, Powerful & Free alternative to ModHeader

Using ModHeader, you can modify http request headers but as a web developer, your debugging needs don’t stop on modifying headers So Requestly offers a complete web debugging solution to Setup URL redirects, Change environments for your JS/APIs, Modify HTTP request & response headers, Modify API Request | Response body & and much more with a simple and powerful UI.

Here’s a quick 2-mins demo video about Requestly:

Download for Chrome

Modify HTTP Request & Response Headers

After Installing Requestly, you can click on the “Create Rule” button and select the “Modify Headers” option to get started. Here’s a quick demo video

Download for Chrome

Step-by-Step Guide to creating Modify Headers Rule

Select Modify Headers option

From the Select Rule options, click on Modify Headers and click on Create Rule button.

Request URL

Define the Request URL (exact URL or URL pattern) on which you want to modify the request or response headers. You can also leave this empty in which case modification will apply to all URLs in your browser.

Select Request Headers or Response Headers

All Request Headers modifications go under the left tab and all Response Header modifications go under the right tab.

Different Modification Options

Add Header
Remove Header
Override Header

Add Header adds a new <header, value> to existing headers. Remove header removes the <header> from existing headers. Override header option only modifies the existing header. If the header doesn’t exist, It won’t add a new header.

Define Multiple modifications

You can combine multiple header modifications for the same URL pattern defined in the rule.

Activate/Deactivate it when not in use

Once you save the rule, you can quickly activate/deactivate it when not in use.

Share with your teammates

You can also share the rules with your teammates with a single click. Just select the rule and click on the Share button to get a link.

Our Users tell a better story

Requestly is used by more than 160,000 developers from 4000+ organizations around the world. We take a lot of pride in providing the best support to our users and making them successful by building the best web debugging solution. Our users love us and so will you.

Was looking for an extension that could redirect/modify header requests, this was the first thing that popped up. I'm not an expert in web dev, and was having a slight issue getting started. Luckily there is a chat feature for assistance, and it turns out the CEO gave me a helping hand to get exactly what I needed! So far this is one of the best extensions I've seen in a long time!

This is an amazing plugin. I also use the desktop application on my mac to modify headers for traffic that comes from Safari or other applications. Works like a charm! I don't know of other tools with the same capability, better than Charles Proxy!

This has been a godsend tool to play around with headers, especially when doing development. Saves a lot of time while developing something and not having to fiddle around with separate config files, just setup your group for say local/stage/prod dev and it magically routes URLs to the correct environments. Best bit is the modify http response, to stub APIs and do web development without having to worry about backends being ready for consumption and also saves up battery to not have to run a backend server at all times, and also helps setup the same API calls for writing tests. Thank you devs for creating such an awesome product!

Download for Chrome