Google Analytics 4 (GA4)

GA4 fully replaced the old Universal Analytics in 2023 and works event-based: every interaction — from page view through view_item and add_to_cart to purchase — is an event with parameters. For stores, e-commerce tracking is the core, making revenue, funnels and product performance analyzable by channel.

In Shopify, GA4 can be connected via the native Google & YouTube integration or a custom setup with Google Tag Manager. The native setup is quick to configure; a GTM setup offers more control over events, parameters and consent logic. Either way, purchase data should be reconciled against the Shopify backend so you understand the discrepancies.

Due to consent requirements, ad blockers and browser restrictions, GA4 systematically measures less than the backend — 10 to 30 percent deviation is normal. GA4 numbers are therefore good for trends and channel comparisons, not as accounting truth. Merchants who need more reliable marketing data combine GA4 with server-side tracking.