GA4 Migration Checklist: Everything Marketing Analysts Need to Verify Post-Migration

If you've migrated to GA4 (or inherited a migration someone else did), there's a high chance things aren't quite right. Based on auditing dozens of GA4 implementations, we've found that 80% of migrations have at least one significant data quality issue.

Here's the complete checklist to verify your GA4 setup is accurate and complete.

Phase 1: Core Tracking Verification

Page View Tracking

• Verify page_view events fire on every page (including SPAs)
• Check that page_location and page_title parameters are populated correctly
• Confirm page_referrer is captured accurately
• Validate that internal traffic filters are configured

Event Tracking

• Confirm all enhanced measurement events are enabled (scroll, outbound clicks, site search, video engagement, file downloads)
• Verify custom events match your measurement plan
• Check event parameter names follow GA4 naming conventions (snake_case, max 40 chars)
• Validate that event parameters contain expected values

E-Commerce Tracking

• Test the full purchase funnel: view_item → add_to_cart → begin_checkout → purchase
• Verify transaction_id is unique and populated for every purchase
• Confirm revenue values match your backend data (±5% tolerance)
• Check currency parameter is set correctly
• Validate item-level data (item_name, item_id, item_category, price, quantity)

Phase 2: Configuration

Conversions

• Mark key events as conversions (purchase, sign_up, generate_lead, etc.)
• Verify conversion counting method (once per event vs. once per session)
• Confirm Google Ads conversion import is working correctly
• Set up conversion value assignment for non-revenue conversions

Audiences

• Recreate key Universal Analytics segments as GA4 audiences
• Set up predictive audiences (likely purchasers, likely churners) if you have enough data
• Verify audiences are being shared with Google Ads for remarketing

Data Retention and Privacy

• Set data retention to 14 months (maximum, required for year-over-year comparison)
• Configure IP anonymization (on by default in GA4)
• Set up Google Consent Mode v2 if you serve EU users
• Verify your consent management platform integrates correctly

Phase 3: Data Quality

• Compare GA4 session/user counts with previous UA data (expect 10-20% variance)
• Check for bot/spam traffic and configure filters if needed
• Verify cross-domain tracking works correctly for multi-domain setups
• Confirm User-ID implementation if you have authenticated users
• Validate that Google Signals is enabled for cross-device reporting

Phase 4: BigQuery Export

• Enable the GA4 BigQuery export (daily and optionally streaming)
• Verify tables are being created daily in BigQuery
• Run validation queries comparing BigQuery data to GA4 interface reports
• Set up scheduled queries for key marketing reports
• Configure access permissions for your analytics team

Phase 5: Reporting

• Build key marketing dashboards in Looker Studio or your BI tool
• Create custom explorations for funnel analysis, path analysis, and cohort analysis
• Set up automated alerts for significant metric changes
• Verify UTM tracking and channel grouping accuracy
• Document your measurement plan and share with the marketing team

Common GA4 Issues and Fixes

• Inflated session counts → Check for duplicate gtag installations or GTM/gtag conflicts
• Missing conversions → Verify events are marked as conversions and data is flowing
• Revenue discrepancies → Compare GA4 purchase events with backend order data
• Bot traffic → Set up data filters for developer traffic and known bots
• Cross-domain issues → Verify linker configuration and test across all domains

Conclusion

A clean GA4 implementation is the foundation of all marketing analytics. Take the time to audit your setup using this checklist — the data quality improvements will pay dividends across every analysis you do. If you find significant issues, prioritize fixing them before investing in advanced analytics.