Understanding, diagnosing, and fixing the data quality issues that make GA4 reports untrustworthy — from silent configuration errors to migration fallout.
Most GA4 properties have at least three data quality problems right now — and most of them are invisible in day-to-day reporting. Every category of failure: what causes it, how to detect it, how to fix it.
Data Quality · AwarenessBad GA4 data hides inside normal-looking reports and produces reasonable-sounding numbers while you make confident decisions based on information that's partially or completely wrong.
Conversion Rate · Data QualityBefore you redesign your checkout — check your tracking. A low GA4 conversion rate is more often a measurement problem than a marketing problem. The six most common causes and how to fix each one.
Concepts · Data QualityA GA4 health score translates dozens of individual configuration and data quality checks into a single number that tells you how much to trust your data.
GA4 deletes your historical data by default after just 2 months. Most properties never change this setting — meaning year-over-year analysis and long-term trends disappear permanently.
Property Setup · Data QualityGA4 defaults to deleting your data after 2 months — silently, automatically, with no warning. Here's what you permanently lose and how to fix it in 30 seconds.
Data Integrity · ConfigurationIf your GA4 property doesn't have a hostname filter, every developer session, QA test, and staging environment visit is counted as a real user. Your data is telling a story that isn't true.
UTM-tagged internal links, payment redirects, and missing cross-domain configuration split single user journeys into multiple sessions — inflating counts and breaking funnel analysis.
Data Integrity · E-commerceGA4 showing double your actual revenue? Duplicate tag firing, thank-you page reloads, and cross-domain checkout issues are the most common causes.
Sessions are lower, bounce rate is gone, and conversions count differently. Most UA vs GA4 discrepancies are architectural — not errors. Here's what actually changed.
Migration · EvergreenMost teams migrated to GA4 — but migrating and migrating correctly are two different things. Data retention deleted, attribution shifted, goals misfired, ecommerce incomplete.