Free GA4 audit in Data Studio (formerly Looker Studio)
Can you trust the data in your GA4? Check it in 5 minutes
The free GA4 audit is a ready-made Google Data Studio (formerly Looker Studio) report that investigates your GA4 property. It catches self-referrals, traffic without a source, UTM errors, personal data in URLs and consent (CMP) implementation problems. Every test is colour-coded green, yellow or red, so you see right away what needs fixing.
- More than 30 data quality tests
- A separate page for e-commerce
- A colour for every test
- Your data never reaches me
Get the GA4 audit
Enter your email and the report link appears straight away on the next page. Then you request view access in the report, which I approve within 24 hours.
The problem
GA4 rarely shows errors. It just collects bad data
The GA4 interface does not warn you when an implementation stops working properly. Reports look normal, and budget decisions are made on distorted numbers. These are the errors I see most often:
Traffic from “nowhere”
Unassigned sessions and inflated Direct. You cannot tell which channel actually sells.
Self-referrals and payment gateways
Your own store or a payment provider such as PayPal, Stripe or Klarna “steals” conversions from your campaigns.
UTM chaos
Capital letters, long mediums and inconsistent names split reports into dozens of rows.
Personal data in URLs
Email addresses in URL parameters risk breaching GDPR and Google Analytics policies.
A broken CMP setup
A misconfigured Consent Mode can duplicate or lose sessions.
This audit checks all of it
Automatically, on your own data. No need to hunt for errors manually in GA4 reports.
Sample result
This is the first page of the audit: the Scoreboard
The Scoreboard sums up every test on a single screen. Below is the result for a sample GA4 property of an online store. The colour of each tile shows at a glance what works and what needs attention.
Example: the Scoreboard page for an online store, data from 6 to 13 October 2026. Each tile links to a page with the details.
What this example shows
Direct traffic
More than two thirds of sessions have no source. The store cannot tell which channels and campaigns actually sell.
Google Ads campaigns
Most Google Ads traffic has the wrong campaign attributed, so campaign reports do not show what works.
URLs with uppercase
The same page is counted as several different URLs, which splits your content data.
This is an automated diagnosis. The colours come from fixed rules in the report, so check the results manually before you start fixing things.
Example for online stores
A separate Scoreboard for e-commerce
When GA4 collects purchase events, the report shows a second Scoreboard page. At the top you see the key sales figures with trends, below the tests of the purchase funnel and of the item_id parameter in 12 e-commerce events.
Example: the e-commerce Scoreboard of the same store, data from 6 to 13 October 2026. The percentages under the figures show the change against the previous period.
Funnel steps
The purchase funnel has all 7 steps in the correct order, and transactions have no invalid IDs or zero quantities.
Events without item_id
Some events, including purchase and begin_checkout, reach GA4 without a product ID. Product reports and remarketing lists are incomplete as a result.
Value outside purchases
Four events other than purchase send a value. Check whether they inflate revenue in your reports.
What the audit checks
Three lines of investigation. More than 30 tests
The GA4 audit checks more than 30 data quality areas in three groups. The report is built like a case file: from the main suspects to routine background checks.
Main suspects
The problems that distort data the most.
- page views with suspected personal data (PII) in the URL
- 404 page views and missing landing pages
- traffic from email and payment gateways
- unassigned users and sessions
- Google Ads campaigns attributed to the wrong channel
- data sampling, messy UTMs and referral spam
Key witnesses
Signs that the configuration is not working as it should.
- pages with a high bounce rate and the share of Direct traffic
- self-referrals and internal UTM tagging
- truncated events and manually collected events
- key event and User-ID configuration
- cross-domain tracking, developer traffic and (not set) hostnames
Background check
Hygiene and property settings.
- content grouping, long mediums, URLs with capital letters
- traffic from AI tools (ChatGPT, Perplexity and others)
- event naming (snake_case) and custom audiences
- demographics collection and the Google Ads link
- suspicious Direct entries on subpages
- the Session Start per Session ratio
1.00
Session Start per Session
Ideally each session has exactly one session_start event. A result from 0.98 to 1.02 means a low probability of problems, and the report marks it yellow. Other values usually point to an error: the bigger the deviation, the more serious it is, for example an extra page reload after the user gives consent in the cookie banner (CMP).
A separate page for stores
- purchase funnel coverage (7 steps) and step order
- the item_id parameter in 12 events, from view_item_list to refund
- transactions without revenue, with an invalid ID or with zero quantity
- purchases by several users under one transaction ID and transactions from self-referrals
- value sent in events other than purchase
- transactions, revenue, purchasers, ARPU and items purchased with trends
These errors make GA4 and Google Ads see different sales than your store.
This is an automated quick audit. The report evaluates data against fixed rules, so it may contain errors, for example marking a deliberate setting in your property as red. Treat it as an indicative diagnosis, not a final verdict on your implementation.
How it works
Four steps to the full picture
All you need is a Google account with access to the GA4 property. No coding, nothing to install on your website and no extra tools.
Your data stays with you. The report runs on your own Google account. You only request view access to the report itself. Everyone sees only the GA4 properties from their own account, so I never see your data.
Leave your email
You get the report link right away on the next page. No waiting for an email.
Request view access
Open the link from the Google account that has access to the GA4 property you want to check, and click “Request access”. I approve requests manually within 24 hours, and Google emails you when access is active.
Choose your GA4 property
Pick your property from the list at the top of the report. The first results appear within seconds.
Read the colours
You can skip green tiles, keep an eye on yellow ones and fix red ones first. Start with the first page, Scoreboard: it summarises all the tests.
Quick audit vs full audit
The report shows symptoms. The causes sit in GTM and on your website
The automated report only sees what has already reached GA4. It cannot look into your Google Tag Manager container, dataLayer or consent banner, so it cannot tell you why an error happened. That is what I check in a full audit.
| Area | Free audit in Data Studio | GA4 and GTM audit |
|---|---|---|
| Unassigned, self-referrals, UTMs | yes, flags the problem | yes, with the cause and the fix |
| Personal data in URLs | flags the page views | the source of the leak and how to fix it |
| CMP and Consent Mode v2 | symptoms, e.g. Session Start per Session | banner, GTM and consent signal configuration |
| E-commerce | funnel and transactions in GA4 | GA4 compared with your store or CRM |
| GTM container and dataLayer | no | yes, tag by tag and event by event |
| Output | a colour and a detail page for every test | a prioritised report and a fix plan for your developer |
| Confidence | an indicative diagnosis, the automation can be wrong | results checked manually in your property |
| Price | €0 | from €190 excl. VAT for simple websites, larger websites: quote after a consultation |
Is this audit for you?
Yes, if
- you run a store or collect leads and judge campaigns by GA4 data
- you took over GA4 from an agency or a former employee and do not know what is set up
- GA4 numbers do not match your store, CRM or Google Ads
- you want to check your data before increasing your ad budget
No, if
- you do not have GA4 on your website yet: start with a GA4 implementation
- you measure a mobile app in Firebase: see app analytics
- you already know tracking is broken and need fixes: go to the GA4 and GTM audit
Who provides the audit
My name is Marcin Miłowski
Day to day I audit and fix GA4 and GTM implementations. This report is the set of tests I run at the start of every project. Now you can run them yourself.
I have worked in analytics and online marketing for more than 11 years and delivered projects for over 150 companies, including app analytics training for Orange and 4F and an analytics implementation for Inter Cars.
Frequently asked questions about the free GA4 audit
Is the audit really free?
Yes. You leave your email and get the full report, with no hidden fees. Only the full GA4 and GTM audit is paid, if you decide to order it.
Why do I have to request access to the report?
Because I share the report only with people who left their email. Requesting view access is a standard Google Data Studio feature. I approve it manually within 24 hours, and Google notifies you by email. Send the request from the Google account that has access to the GA4 property you want to check.
Do I have to give you access to my GA4?
No. You only request view access to the report itself, from the Google account that has access to the GA4 property. The report pulls data through your own login and everyone sees only their own properties, so I never see your data or results.
Do I need technical knowledge?
No. A Google account and GA4 access with the lowest role that allows viewing reports are enough. The colours show what matters, and every tile leads to a detail page.
Does the report work for every website?
Yes, for every GA4 property, including lead generation websites. The e-commerce page adds extra transaction and purchase funnel tests.
Are the audit results certain?
Not 100%. This is an automated quick audit that evaluates data against fixed rules, so it may contain errors. Treat it as an indicative diagnosis. Certainty only comes from manually checking GA4, GTM and the consent banner in a full audit.
I have red tiles. What next?
Fix them first, because they distort data the most. Every tile leads to a detail page. If you want my help, take a screenshot of the report’s first page (Scoreboard), send it to [email protected] and book a free 30-minute consultation in my calendar. I have no access to your data, so the screenshot lets me check the results manually before we meet.
Will you send me a newsletter?
No, unless you tick the consent to receive news about new report versions. If you tick the contact consent, I will write to you personally at most once to ask whether the audit was useful. I do not sell or share addresses with other companies.
Can I send the report to my developer or agency?
Yes. Send them the same link. They will see the results if they have access to the same GA4 property.
Check your GA4 before you spend your next ad budget
More than 30 tests on your own data, results within minutes of getting access. You get the report link right after entering your email.