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analytics-dictionary / term / tracking & measurement

Data layer

The data layer is a JavaScript object on your site that holds structured information for your tag manager to read.

Written by Reflective Data experts · updated Oct 5, 2026

Instead of scraping text from the page, developers push events and values, such as a product list or a user type, into the data layer. Tags then read from it.

A clean data layer decouples tracking from the page design, so a redesign does not break your analytics.

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