sGTM - add X-Gtm-Server-Preview Header is a Chrome extension developed by Nikel, available for free in the Browsers category under Add-ons & Tools. This tool offers a great solution for debugging the Server-Side Tag Manager and GA4 setups. It provides two essential features for efficient tracking setup debugging.

The first feature automatically adds the X-Gtm-Server-Preview header to all requests, ensuring smooth debugging without causing any unpredictable behavior. Unlike other plugins, this extension includes an auto-deactivation feature that turns off after an hour, enhancing the debugging process. The second feature adds a _dbg=1 parameter to all GA4 requests, simplifying the debugging process for GA4 setups.