# Google Analytics 4 + PostHog integration and analysis

Connect Google Analytics 4 and PostHog to Hendrik. Compare GA4 traffic and event reporting with PostHog captured events and sessions to locate instrumentation or scope differences.

## The question this stack can answer

Why do GA4 and PostHog tell different stories about the journey?

## What Hendrik reads from each source

- **Google Analytics 4:** Traffic acquisition, landing pages, and on site events show where the website journey changed.
- **PostHog:** Events, sessions, releases, and feature flags show whether the product or checkout journey changed.

## What you need to connect

- Use one explicit 28-day comparison window, time zone, market, and legal-entity scope before comparing values.
- Connected GA4 property with comparable acquisition and event reporting.
- Connected PostHog project with the relevant event definition and capture coverage.
- Keep provider-specific definitions visible and use an identity or product mapping only where it is established for this workspace.

## Important limits

- GA4 events and attribution do not automatically establish a paid order, payment, or campaign relationship.
- Captured events depend on instrumentation and coverage; they do not automatically identify a payment, order, or campaign.

## Illustrative example

### Google Analytics 4 + PostHog review

Previous: 1–28 January. Current: 29 January–25 February. Both periods contain 28 days. Monetary values use USD and all timestamps use UTC.

*About this example: Synthetic data · illustrative analysis · Hendrik only acts with the permissions you give it.*

- reported purchase events (count, 28 days) (Google Analytics 4): 1,420 → 1,230
- checkout-completed events (count, 28 days) (PostHog): 1,360 → 1,160
- GA4 paid sessions (configured channel group, consecutive 28-day periods) (Google Analytics 4): 16,800 → 15,300

### What Hendrik checks

- **Traffic measurement:** Check GA4 property, timezone, consent coverage, source definition, and event configuration before comparing sessions or transactions.
- **Event and release context:** Check PostHog event definition, instrumentation coverage, feature-flag exposure, annotations, and session scope before interpreting a journey change.
- **Explain the divergence:** Google Analytics 4: reported purchase events (count, 28 days) changed from 1,420 to 1,230. PostHog: checkout-completed events (count, 28 days) changed from 1,360 to 1,160. Compare the timing and definitions before attributing one change to the other.

### What Hendrik sees

GA4 reported purchase events and paid sessions fell. PostHog checkout-completed events fell.

### What to do next

Document the measurement difference before using either metric for an acquisition decision; reassess after the relevant tracking setup is stable.

**Limit:** The two analytics tools can observe different populations and should not be treated as reconciled counts.

## Provider documentation

- [Google Analytics 4 documentation](https://support.google.com/analytics/)
- [PostHog documentation](https://posthog.com/docs)

## Start with this stack

[Create a workspace and connect Google Analytics 4 + PostHog](https://app.withhendrik.com/auth?mode=sign-up&acquisition_channel=marketing&return_to=%2Fonboarding%2Factivation&cta_location=integration_markdown&landing_page_id=combination-ga4-posthog&combination=ga4-posthog)