Free GA4 Audit Tool - Check your Google Analytics

GA4 is the standard today – and at the same time one of the most frequent causes of incorrect marketing decisions. Not because Google Analytics 4 is “bad”, but because the measurement chain has become more complex: consent, browser restrictions, event-based tracking, e-commerce implementations, cross-domain flows, payment providers.

At our webmastering firm, Prange , this led to a very simple situation: We constantly had to check the same things during GA4 setups – and the manual approach was time-consuming and annoying. So we built a tool to automate our auditing work. The result is the GA4 Auditor .

👉 Try it for free: ga4-auditor.dev

The problem: A GA4 audit is mandatory – but it takes time.

A proper GA4 audit doesn’t consist of “just quickly looking at the reports”. It examines the setup and the data reality .

Typical symptoms in projects:

“(not set)” in pages, sources, or campaigns
Direct is suspiciously high
Self-referrals or payment referrals destroy attribution.
Sales figures in GA4 do not match the shop system
Duplicate purchases lead to an “excessively high” ROAS.
A quick quality assurance check is lacking after deployments.

A manual audit by an experienced analyst typically takes 4–8 hours – and after every change, you essentially have to recheck everything. That’s exactly what we wanted to solve.

The idea: Same tests, but in minutes – repeatable at any time

The GA4 Auditor automates precisely these standard checks:

Live configuration via the GA4 Admin API
Real-time check to see if events are actually being well received
Optional (if enabled): In-depth analysis of the last 30 days via BigQuery export

The result is a dashboard with traffic light logic :

Passport : no irregularities
Warning : Risk/setup gap that frequently leads to false reports
Fail : high probability of a genuine tracking or data problem

What the GA4 auditor checks – on three levels

1) Health Checks (quick)

Fast setup and data quality checks based on the GA4 APIs.

2) Traffic light checks (prioritized)

Compressed evaluation (Pass/Warning/Fail) with a focus on BigQuery raw data checks .

3) SST analysis (server-side – pragmatic)

Technical assessment of whether and where server-side tracking makes sense and where measurable problems exist today.

Data sources: What is used for what purpose?

GA4 APIs

GA4 Admin API : Configuration & Setup (Streams, Enhanced Measurement, Key Events, Google Ads Linking, BigQuery Linking, Custom Definitions, Annotations)
GA4 Data API : Aggregated plausibility check (channel shares, page title patterns, e-commerce signals, site search)

Note: The Data API is often delayed. Therefore, checks are designed to ensure that the evaluation remains stable.

BigQuery Export (Deep Analysis)

When BigQuery export is enabled, the app uses raw data from the export. This allows for in-depth checks such as:

PII clues (e.g., email/phone in URLs) via regex scan
Duplicates (Events/Transactions)
Query parameter pattern
Payment referrals
Funnel consistency (Add-to-cart → Checkout → Purchase)

Examples: Checks that actually cost money in practice

Self-referrals

Own domain appears as referrer → Sessions split, attribution breaks, campaigns “lose” conversions.

Payment referrals (PayPal/Klarna/Stripe)

The purchase is suddenly counted as a referral from the payment provider → ROAS and channel rating are reversed.

Duplicate Transactions

Purchase is sent multiple times (reload to thank-you page, double firing, back navigation) → revenue/ROAS is distorted.

“(not set)” as a permanent state

Missing data renders reports unusable – and obscures the underlying causes.

PII in URLs (Compliance)

Personal data in URLs poses a real risk and must be identified and stopped early.

Bot and session anomalies

Unrealistic event frequencies or sessions without a start event distort KPIs.

How to use the GA4 Auditor effectively (workflow)

Starting with the overview : Are the setup and basic data generally correct?
Open Warnings/Fails : View details + specific to-dos
Delve deeper into data problems in BigQuery : Raw data almost always reveals the cause
For attribution/browser gaps/consent effects : Use the SST area to assess impact and priority.

Quickstart: Get your first results in 5 minutes

Log in and select property (viewer rights are sufficient)
Run the audit

API checks: seconds
Deep Analysis (30 days via BigQuery): typically 1–2 minutes (depending on the data volume)

Prioritize the top 3 fails

Often the biggest leverage is: Payment/self-referrals and e-commerce payload.

Security: Does the tool interfere with your property?

No.

The GA4 Auditor only requires read permissions .
No settings will be changed .
Nothing is saved .

Why the tool is free

We developed the GA4 Auditor to standardize our own auditing and debugging work.

When a tool ensures that the data basis is updated more quickly, everyone benefits:

Marketing teams make decisions on a sound basis
Analysts find causes faster
Agencies can scale audits

And: Anyone who realizes that the database cannot be fixed “just like that” also knows when to seek support.

Videos about the GA4 Auditor

GA4 Auditor App – 50+ Google Analytics Checks

This video gives you a quick overview of how the G4 Auditor app works and which checks it automatically performs for Google Analytics 4.

Server-side tracking test in GA4 Auditor

In this video I will show you the Server-Side-Tracking tab and how you can quickly assess whether Server Side Tracking (SST) really makes sense for a GA4 property – and how big the expected impact is.

Session debugging with BigQuery

In this video, I’ll show you how to debug sessions directly via the GA4 BigQuery export using the GA4 Auditor – without waiting 72 hours for data to appear in the GA4 UI. You’ll see in (almost) real time whether your fixes are working in Google Tag Manager.

When we help

If the auditor identifies systemic issues (consent, cross-domain, server-side, e-commerce tracking, Google Ads linking), we provide support with:

GA4/Tagging QA and audit fixes
E-commerce event plan + clean payloads
Cross-domain tracking and referral problems
Server-side tracking (including BigQuery/Matomo setups)
Integration with Google Ads and clean conversion handover

Conclusion

GA4 is only as good as the data that arrives.

If you no longer feel like spending hours manually searching for symptoms, use the GA4 Auditor as a quick, repeatable health check – and only delve deeper where there is a real problem.