GA4 Audit Template: Ensuring Data Accuracy in Google Analytics

Amazingly GA4 has been around for almost 3 years now. Even before it's October 2020 release date it existed in beta under the name App + Web. During this early period, the consensus within the analytics industry was to set it up as soon as possible to start collecting data.

As we got closer to the Universal Analytics deprecation date, those behind the curve were scrambling to get GA4 set up as soon as possible.

I've seen that both these drivers led many organisations to jump on board to start collecting data in GA4, but not everyone took the time (or had the expertise) to ensure proper configuration.

This audit template is your tool to identify potential issues and restore trust in your GA4 data, enabling confident decision-making.

The audit checks are categorised into four sections:

Data Collection
Configuration
Data Protection
Data Quality & Reporting

ACCESS THE TEMPLATE

How to use the audit template

Start with the checks tab, go through each assigning a score between 1-5
Collate any recommendations that come out of these checks on the recommendations tab
Document the events and parameters that are currently set up on the events and parameters & custom definitions tabs
The unique parameters tab is just a tool to help you identify all the unique parameters that are listed in the events tab and check if those parameters have been documented in the parameters & custom definitions tab. This can be deleted once you've finished the audit
Finally, summarise the audit on the summary tab. The average scores will pull through to this tab from the checks tab - ensure that you enter a score between 1 - 5 for all checks.

Data Collection

GA4 Configuration Tag

The GA4 configuration tag initialises GA4, handling cookie settings, automatic event tracking, and common configurations. Ensure it's present on every page and loads only once per page, keeping settings under 'fields to set' static for all events on the page.

Enhanced Measurement

Review if enhanced measurement is in use. While it's suitable for beginners, consider setting up events in Google Tag Manager (GTM) for maximum control over data collection.

GA4 Events

Evaluate the events in GA4. Ensure they follow best practices, use snake_case event names, and consolidate events and parameters to avoid limits. Leverage Google's recommended events where applicable to capture all key interactions on the site.

GA4 Event Collection Limits

Check for signs that the property is nearing event collection limits, such as the 25-parameter limit and character limits for parameter names or values. Monitor proximity to the 1M events per day limit for free GA4 with BigQuery integration.

Google Tag Manager (GTM)

Assess if GTM is used for all web tracking. Verify consistent naming conventions, identify and remove unused elements, and utilise built-in tags, triggers, and variables. Explore opportunities to use GTM templates and review non-GA tags.

Data layer

Examine the extent of data layer usage and identify any issues or opportunities for a more robust tracking setup using the data layer.

Data Streams

Check the number of data streams and their functionality. Google recommends one web data stream per property and one app stream per app instance. Ensure no data streams are associated with test environments, as separate properties are recommended for them.

Measurement Protocol

Inspect for Measurement Protocol API secrets, indicating potential usage of this feature to send GA4 hits from various devices or platforms.

Connected Site Tags

Evaluate the use of connected site tags. Note that this practice is not recommended in most cases.

Configuration

Industry Category

Review the selected industry category. In GA4, there are currently no benchmarking reports, so this choice doesn't significantly impact your data.

Reporting Time Zone

Ensure the reporting time zone aligns with other platforms, especially Google Ads, to avoid discrepancies.

Currency

Set the currency to match the main currency used in the GA4 property. For multiple currencies, include currency conversion in e-commerce tracking.

User Management

Assess the number of people with access to the GA4 property. Periodically review and remove access from those who no longer require it, particularly admin or editor access.

Event Modifications

Check if event modifications are made directly within GA4. The best practice is to implement event tracking through GTM for greater control.

Configure Domains

Verify that all tracked domains are configured properly. Cross-domain measurement should work seamlessly when all relevant domains are added.

Collect Universal Analytics Event

Evaluate if this setting is used to send GA4 events for existing Universal Analytics events. This feature is generally not recommended.

Unwanted Referrals

Assess and manage unwanted referrals, ensuring proper attribution of conversions and accurate traffic source data.

Session Timeout

Review session timeout settings. Adjust if necessary to prevent sessions from ending prematurely, especially for long-duration content.

Timer for Engaged Sessions

Examine the timer for engaged session settings. Adjust the threshold for defining engaged sessions based on your organisation's needs.

Override Cookie Settings

Check for overridden cookie settings. This can impact user identification, so review if this feature is in use.

Google Signals

Evaluate the use of Google Signals, which provides cross-platform reporting and demographic insights. Be aware of thresholding issues related to low user counts.

Data Filters

Determine if IP filters are configured in GA4, especially for filtering internal traffic. Assess the impact based on your organisation's size, tendency for remote work, and IT infrastructure.

Data Import

Review data import settings, check if it's in use, and verify data accuracy in reports.

Reporting Identity

Inspect the reporting identity settings, which affect user identification methods. Choose the appropriate method based on your organisation's needs.

Attribution Settings

Check the selected attribution model in GA4. Consider discussing the model with stakeholders to ensure it aligns with your organisation's goals.

GA4 Configuration Limits

Assess if the property is approaching any configuration limits, such as custom dimensions. Be mindful of naming conventions that could lead to reaching these limits.

Data Protection

Personally Identifiable Information (PII)

Ensure that PII is not collected within GA4, as it violates Google's terms of service and data protection regulations. Identify sources of PII and take corrective actions.

Data Retention

Review data retention settings in GA4, aligning them with your organisation's data protection policies. Understand the impact on custom reports in Explore.

User ID

If a User ID is used, ensure it doesn't contain PII and that the privacy policy discloses identifier usage, without revealing individual identities.

Consent Management

Confirm the presence and integration of a Consent Management Platform (CMP) to allow user tracking preferences. Review categorisation and user-friendly options for preference changes.

Data Quality & Reporting

Tracked Hostnames

List all tracked hostnames and verify the inclusion of relevant domains. Ensure consistency with user journeys.

Sampling

Check event volume and potential sampling in GA4 exploration reports, which occurs after reaching 10M events within the query for free GA4.

Cardinality

Identify dimensions with high cardinality (>500 unique values per day) that could impact reports. Be aware of row consolidation in reports.

Thresholding

Understand thresholding effects related to Google Signals and low user counts. Consider switching to device-based reporting if needed.

Channel Reports & UTM Tagging

Review traffic categorised as 'unassigned' in channel reports. Assess UTM tagging practices and opportunities for clearer tagging.

Custom Dimensions & Metrics

Inspect custom dimensions and metrics setup in GA4 UI. Document them thoroughly and ensure appropriate scope.

Conversions

Check for configured conversions reflecting your organisation's KPIs, allowing easy analysis and optimisation.

E-commerce

Evaluate e-commerce tracking completeness and accuracy, ensuring the full e-commerce journey is tracked from viewing items in a list all the way to purchase.

Audiences

Assess the use of audiences for segmentation and targeting. Explore opportunities to create new audiences for analysis and optimisation.

Reporting Interface

Review customised reporting interfaces for issues and improvements in categorisation.

Content Grouping

Check if the content_group parameter is populated and explore other custom parameters for content grouping. Optimise content performance analysis.

Integrations

Examine integrations with various products such as Google Ads, Ad Manager, BigQuery, DV 360, Merchant Centre, Search Ads 360, Search Console, and Firebase.

Ensure proper configuration and data synchronisation where applicable.

Conclusion

If you or your colleagues don't trust your GA4 data, a meticulous GA4 audit will help to ensure data accuracy and restore that trust. By addressing the four main areas covered (configuration, data collection, data protection, and data quality) you empower your organisation to once again make confident decisions based on reliable data.