GA4
Google Analytics 4 is a fundamentally different analytics product from Universal Analytics. It is event-based rather than session-based, built for privacy constraints from the start, and designed with BigQuery integration as a first-class feature. If you are coming from Universal Analytics, expect to relearn most of your assumptions about how data is structured and how reports work.
This section covers everything from initial property setup to writing complex SQL queries against your BigQuery export.
Fundamentals
Section titled “Fundamentals”Start here if you are new to GA4 or need to understand how the data model works before configuring anything.
Data Model How GA4's event-based model works — events, parameters, and why this is different from session-based analytics.
Events, Parameters, and User Properties The three building blocks of GA4 data collection and how they map to the interface.
Sessions and Attribution How GA4 defines sessions, applies attribution, and why your numbers differ from UA.
Data Streams Web, iOS, and Android streams — configuration, measurement IDs, and cross-platform considerations.
Measurement Protocol Send events directly to GA4 from servers, IoT devices, or any environment without a browser.
Measurement Protocol Debugging Validate Measurement Protocol hits and diagnose why server-side events are not appearing.
Configuration
Section titled “Configuration”Property-level settings that determine what gets collected, how it is classified, and what reports surface.
Property Setup Creating and configuring a GA4 property from scratch — the non-obvious settings that matter.
Custom Dimensions Extend GA4's data model with your own event and user-scoped dimensions.
Custom Metrics Track numeric values that GA4 doesn't collect natively — revenue variants, engagement scores, counts.
Audiences Build remarketing and reporting audiences from GA4 events and conditions.
Conversions Mark events as conversions and understand how GA4 counts them differently from goals.
Data Filters Exclude developer traffic, internal users, and testing sessions from your GA4 data.
Channel Groupings Customize how GA4 classifies traffic sources — fix misclassified channels and add custom rules.
Attribution Settings Data-driven vs. last-click attribution and how model changes affect historical data.
Enhanced Measurement Pitfalls The auto-tracking features that cause double-counting, missed events, and bad data.
Data Limits and Cardinality The hard limits that will bite you — custom dimension quotas, (other) rows, and cardinality thresholds.
Calculated Metrics Create derived metrics in GA4 without touching BigQuery — revenue per user, conversion rates, ratios.
Reporting
Section titled “Reporting”How to use GA4’s built-in reports and explorations to answer real business questions.
Standard Reports Navigation, customization, and what each standard report actually measures.
Explore Reports Free-form analysis — when to use explorations over standard reports and how to build them.
Funnel Exploration Visualize drop-off through multi-step funnels with open and closed funnel modes.
Path Exploration Understand user journeys forwards and backwards from any event.
Segment Overlap Identify users who belong to multiple segments and analyze cross-segment behavior.
BigQuery
Section titled “BigQuery”Raw access to your GA4 data — no sampling, no cardinality limits, full SQL power.
Export Setup Link GA4 to BigQuery and configure daily vs. streaming export.
Schema Reference Complete field reference for the GA4 BigQuery export schema.
Common Queries Ready-to-use SQL for the most frequent GA4 BigQuery analysis tasks.
Session Reconstruction Rebuild sessions from raw event data in BigQuery — the canonical approach.
Funnel Analysis in SQL Build flexible, unsampled funnels in BigQuery that go beyond GA4's built-in funnel tool.
Cost Optimization Keep BigQuery costs under control with partitioning, clustering, and query best practices.
Unnesting Patterns Work with GA4's nested ARRAY and STRUCT fields — the patterns you'll use in every query.
Custom Channel Grouping Replicate and extend GA4's channel grouping logic in BigQuery SQL.
Attribution Queries Implement first-touch, last-touch, and linear attribution models in BigQuery.
Dataform Workflows Build modular, tested, incrementally-updated GA4 data models with Dataform.
Looker Studio Patterns Connect GA4 BigQuery data to Looker Studio — custom queries, blending, and performance.
Troubleshooting
Section titled “Troubleshooting”Diagnose and fix data quality issues before they become reporting problems.
Data Discrepancies Why GA4 numbers don't match your other tools and how to determine which source is correct.
Missing Data Diagnose why events, conversions, or dimensions are absent from your reports.
DebugView Use GA4's real-time debug mode to validate your implementation event-by-event.
Realtime Validation Use the Realtime report and DebugView together for pre-launch implementation checks.
Common Mistakes The implementation errors that show up in nearly every GA4 setup and how to fix them.
Internal Traffic Filtering Exclude your own team's traffic from GA4 reports using IP-based and developer filters.
Programmatic access to GA4 data and configuration.
Data API Query GA4 reports programmatically with Python and Node.js — the same data as the UI, via code.
Admin API Manage GA4 properties, streams, and custom dimensions programmatically.
User Deletion API Delete user data from GA4 for GDPR compliance and right-to-erasure requests.