Product
HTTP Interceptor

A Power HTTP Interceptor to Intercept, Record, Debug & Modify HTTP Requests

API Client

A lightweight and secure API Client for faster API Development & Testing

API Mocking

Build frontend faster without waiting for backend.

Solutions
Frontend Web/Mobile Developers

Requestly improves front-end workflows with local JS testing, mocking, and SessionBook debugging.

For QA engineers

QA engineers love Requestly for its features and ease of use, allowing easy edge case testing.

Support Engineer

Support engineers value Requestly for debugging, demoing, and overriding GTM and Adobe scripts.

Backend Developers

Requestly helps in improving back-end development workflows, by enabling testing.

Pricing
Resources
Pricing
Blog
Case Studies
Status
Github
Release Note
Student Programme
🎉 Requestly joins BrowserStack to build the future of application testing. Read more

HTTP Headers

Sec CH UA Platform

HTTP Header

Experimental: This is an experimental technology
Review the browser compatibility table carefully before deploying this in production environments.

Secure context: This feature is accessible only within secure contexts (HTTPS) in some or all supported browsers.

The HTTP <strong>Sec-CH-UA-Platform</strong> request header is a user agent client hint that provides information about the platform or operating system where the user agent is running.
For example: “Windows” or “Android”.

<code>Sec-CH-UA-Platform</code> is a low entropy hint.
Unless blocked by a user agent permission policy, it is sent by default (without the server explicitly requesting it through sending <code>Accept-CH</code>).

Header typeRequest header,
Client hint
Forbidden request headerYes (<code>Sec-</code> prefix)

Syntax

Sec-CH-UA-Platform: <platform>

Directives

One of the following strings: "Android", "Chrome OS", "Chromium OS", "iOS", "Linux", "macOS", "Windows", or "Unknown".

Example

Examples

Using Sec-CH-UA-Platform

As Sec-CH-UA-Platform is a low entropy hint, it is typically included in all requests. A browser running on a macOS device might add the following header to each request:

  Sec-CH-UA-Platform: "macOS"

How to Modify Header using Requestly

Requestly is a powerful Chrome extension that allows you to modify HTTP headers, including the Sec-CH-UA-Platform header. This is especially useful for testing how your application behaves when different platform information is sent in the user agent client hints. Steps to Modify the Sec-CH-UA-Platform Header:

  1. Install and open the Requestly Chrome extension. You can find it on the Chrome Web Store.
  2. Create a new rule: Click on “Create Rule” and choose “Modify Headers” from the list of available rule types.
  3. Add a new header modification:
    • Under “Action”, select “Add” or “Override”.
    • In the “Header Name” field, enter Sec-CH-UA-Platform.
    • In the “Header Value” field, enter your preferred platform string (e.g., “Windows” or “Android”).
  4. Set the URL condition: Specify the URL or pattern where this header change should apply (e.g., https://your-api.com/*).
  5. Save the rule.

Once set up, Requestly will inject the Sec-CH-UA-Platform header with your chosen value into all matching requests, allowing you to simulate different platform environments and test how your application adapts to varied client platforms.

Modifying the Sec-CH-UA-Platform header helps you understand how your site or app responds to different operating systems or platforms without needing actual devices, making testing easier and more efficient.