A tag manager is a tool that allows measurement and marketing codes to be added to a website without editing the page's source code. A single container is inserted into the site once, and everything else is then managed through an interface – analytics scripts, ad-system conversion codes, session-recording tools or chat. The advantage is speed and marketing's independence from developer capacity; the disadvantage is the risk of clutter, as dozens of scripts accumulate over time that no one knows the purpose of and that slow the website down. Consistent naming, a note with every change, and a regular review therefore prove their worth. The tool works with versions and a preview, so every change can be tested before publishing and rolled back if there is a problem.
See also: Data layer, Event tracking, Consent mode in analytics.
