Debugging mode in Google Tag Manager

Preview mode allows you to verify the correctness of Google Tag Manager tag settings before publishing a container, to identify current problems during the testing phase and to reduce the risk of their occurrence in the future. Preview mode in GTM is also called debug mode.

Variables in GTM

A variable in Google Tag Manager is an object that is given a name and can take on different values (like a key-value pair). The name of the variable is constant, and its value changes depending on what actions are taking place on the site. The obsolete name for a variable in the previous version of Google Tag Manager was macro.

Google Tag Manager

Google Tag Manager (GTM) is a free tag management system that allows you to easily add and update measurement and marketing tags on your website or mobile app without having to modify the code.