Sec,ch,ua,arch:,""x86"" Apr 2026

Historically, developers had to "sniff" the User-Agent string—a messy process prone to errors and spoofing. Sec-CH-UA-Arch provides a cleaner, structured way to:

: On the next request, the browser will include: Sec-CH-UA-Arch: "x86" Accessing via JavaScript sec,ch,ua,arch:,""x86""

If you need this information on the client side, you can use the NavigatorUAData API . Because it is high-entropy data, it returns a Promise: Detecting Microsoft Edge from your website This HTTP request header tells a server exactly

To see this header in your server logs, you must first "opt-in" by sending an Accept-CH response header to the browser. : Tailor resource-heavy scripts or assets to the

This HTTP request header tells a server exactly what kind of processor instruction set the browser is running on. When you see Sec-CH-UA-Arch: "x86" , it indicates the device is powered by an Intel or AMD processor, as opposed to "arm" architectures common in mobile devices and newer MacBooks. Why Does It Matter?

: Tailor resource-heavy scripts or assets to the specific hardware capabilities of the user's machine.