Best Practices and Key Metrics for Google Tag Manager Audits

Best Practices and Key Metrics for Google Tag Manager Audits

Review tags, triggers, and variables for accuracy; focus on tag firing and page load impact. Audits ensure precise data collection and optimal performance.

By: Menahil Shahzad | 5 mins read
Published: Jun 10, 2024 3:47:44 AM | Updated: Jun 16, 2024 04:51:25 AM

Are you overwhelmed by the intricacies of Google Tag Manager (GTM)? 

Need help keeping your tags and triggers in check? You're not alone. 

Many marketers and web analysts need help managing GTM effectively 

This blog will explore the best practices and key metrics for conducting a thorough Google Tag Manager audit, ensuring your implementation is streamlined, efficient, and headache-free. 

Whether you're a GTM consultant, user, or just a beginner, these insights will help you optimize your setup and improve your tracking accuracy.

Need help from GTM Experts?

Get in touch to learn about Analytico’s Digital Analytics Audit services or GA4 audit services

Google Tag Manager

Google Tag Manager

GTM is a powerful tool that allows marketers and developers to deploy and manage tags on their website or mobile app without the code directly. 

Tags are snippets of code used to collect data and send it to various analytics and marketing platforms. 

By centralizing tag management, GTM simplifies updating and managing these tags, enhancing site performance and accuracy.

Why Conduct a GTM Audit?

Google Tag Manager Audit

Regular audits of your GTM setup are essential to ensure:

  • Data Accuracy: Ensure all tags are firing correctly and collecting the intended data.
  • Performance Optimization: Identify and remove redundant or outdated tags that may slow down your site.
  • Compliance: Ensure your tagging implementation adheres to privacy regulations like GDPR or CCPA.
  • Efficiency: Optimize your tag management to streamline processes and improve tracking efficiency.

Best Practices for Google Tag Manager

Google Tag Manager Best Practice

1. Organize Your GTM Workspace

The best way to organize your Google Tag Manager WorkSpace is by renaming conventions, categorizing tags, and making separate versions. 

  • Naming Conventions

Use clear and consistent naming conventions for tags, triggers, and variables, For example, name tags with a prefix indicating their type as GA-Pageview, or FB-Pixel.

  • Folders:

Utilize folders to categorize tags, triggers, and variables by their function or the platform they belong to.

2. Use a Consistent Version System

  • Version Control

Before publishing any changes, create a new version of your container. This allows you to roll back to a previous version if something goes wrong.

  • Document Changes

Maintain a changelog for each version detailing what changes were made and why. This aids in tracking the evolution of your tags and troubleshooting issues.

3. Implement Data Layer Standard 

  • Data Layer Structure

Maintain a well-structured data layer. Consistent naming conventions and a clear structure make it easier to manage and debug.

  • Custom Events

Use custom events to track specific interactions covered by standard tags. This allows for more precise and actionable data collection​ 

4. Efficient Tag Management

  • Limit the Number of Tags

Avoid adding too many tags as they can slow down your site. Periodically review and remove any tags no longer necessary for effective GTM tracking.

  • Asynchronous Tagging

Use asynchronous tags whenever possible to ensure that they do not block the rendering of your website.

5. Use Built-in Variables

  • Built-in Variables

Utilize GTM’s built-in variables for common tasks instead of creating custom ones. This reduces complexity and potential errors.

  • Custom Variables

Use custom variables like Java Script for more complex data manipulations. This allows you to extract and use specific data points from your site.

6. Regular Testing and Debugging

  • Preview Mode

Always use GTM’s preview mode before publishing changes. This allows you to test if tags are firing correctly.

  • Tag Assistant

Use the Google Tag Assistant Chrome extension to verify that your tags are implemented correctly on live pages​.

  • Debugging Tools

Use browser developer tools and GTM’s debugging console to inspect the data sent to your analytics platforms.

7. Minimize the Use of Custom HTML Tags

  • Built-In Tags

Use GTM’s built-in tags for Google Analytics, AdWords, and other platforms. These tags are optimized for performance and are easier to manage.

  • Custom HTML

If you must use custom HTML tags, keep the code clean, efficient, and well-documented to avoid performance issues and maintenance headaches.

8. Establish a Governance Process

  • Permissions

Set appropriate user permissions to control who can view, edit, and publish changes. This helps prevent unauthorized modifications.

  • Review Process

Implement a review process by another team member before being published. This adds a layer of quality control.

9. Monitor and Audit Regularly

  • Tag Audits

Regularly audit your GTM container to remove unused tags, triggers, and variables. This keeps the container clean and efficient.

  • Performance Monitoring

Monitor the performance of your tags to ensure they are not slowing down your website. Use tools like Google PageSpeed Insights for this purpose.

10. Use Triggers Wisely

  • Specificity

Create specific triggers that only fire under the precise conditions needed. This prevents tags from firing unnecessarily and improves data accuracy.

  • Exceptions

Use exception triggers to prevent certain tags from firing under specific conditions. This helps control your tag execution.

11. Tag Management and Documentation

  • Tag Inventory

Maintain an inventory of all tags, triggers, and variables in your GTM container. This inventory should include purpose, configurations, and any dependencies.

  • Documentation

Thoroughly document the purpose and configuration of each tag, trigger, and variable. This aids in onboarding new team members and ensures continuity in tag management.

Key Metrics for GTM Audits

Google Tag Manager Audit, GTM Consultant

1. Tag Accuracy and Performance

  • Tag Firing Rate

Ensure that tags are firing on the intended pages and events. Incorrect firing can lead to data discrepancies.

  • Page Load Impact

Monitor the impact of tags on page load times. Tags that significantly slow down your site should be optimized or removed. Keep track of and fix any 404 error pages in GTM

2. Data Collection Integrity

  • Duplicate Tags

Check for duplicate tags, especially for important tracking like Google Analytics or Facebook Pixel. Duplicate tags can inflate metrics.

  • Data Layer Consistency

Verify that the data layer is consistent across all pages. Inconsistencies can lead to inaccurate data collection​.

3. Tracking metrics

  • Conversion Tracking Accuracy:

Validate that conversion tags are firing correctly and recording accurate data for all relevant actions.

  • User Engagement Metrics:

Use GTM to track user engagement metrics such as clicks, form submissions, and video plays, ensuring interactions are correctly measured.

  • Container Size:

Keep an eye on the size of your GTM container to avoid bloat, which can negatively impact site performance.

4. Compliance and Privacy

  • Consent Management

Ensure tags comply with consent management policies (e.g., GDPR, CCPA). Tags should not fire until user consent is obtained.

  • PII Compliance

Make sure no personally identifiable information (PII) is being collected unless explicitly allowed by your privacy policy and user consent.

5. Tag and Trigger Optimization

  • Unused Tags and Triggers

Identify and remove tags and triggers that are no longer in use. This helps a clean and efficient setup.

  • Trigger Efficiency

Optimize triggers to ensure they are as specific as possible, reducing the chance of unnecessary tag firing​​.

Step-by-Step GTM Audit Process

GTM, Google Tag Manager, GTM Consultant

1. Preliminary Setup

  • Backup Current Container

Export the current GTM container to keep a backup before making any changes.

  • Access Rights:

Ensure you have the necessary permissions to make changes to the GTM account.

2. Review and Document Current Setup

  • Tag Inventory

List all the tags currently in use and their purposes.

  • Trigger Review

Document all triggers and the conditions under which they fire.

  • Variable Audit:

List all variables, including their types and use cases.

3. Data Layer Audit

  • Structure Check

Review the data layer structure for consistency and completeness.

  • Custom Events

Verify that custom events are correctly implemented and firing.

4. Tag Firing Verification

  • Test Environment

Use GTM’s preview mode to test each tag in a controlled environment.

  • Live Verification

Use tools like Google Tag Assistant to verify that tags are firing correctly on live pages.

5. Performance Analysis

  • Load Time Impact

Use performance monitoring tools to assess the impact of tags on page load times.

  • Tag Management

Remove or consolidate tags that negatively affect performance.

6. Compliance Check

  • Consent Implementation

Verify that consent management is properly implemented and that tags respect user preferences.

  • PII Protection

Ensure no PII is being inadvertently collected by reviewing the data sent by tags.

7. Optimization and Cleanup

  • Remove Redundant Tags

Eliminate any tags, triggers, or variables no longer in use.

  • Optimize Triggers:

Refine trigger conditions to ensure they are specific and efficient.

  • Documentation Update

Update your GTM documentation to reflect any changes made during the audit.

Post-Audit Best Practices

1. Continuous Monitoring

  • Regular Reviews

Schedule regular audits to ensure the ongoing accuracy and efficiency of your GTM setup.

  • Automated Alerts

Set up automated alerts for critical tags to get notified of any issues. 

2. Training and Documentation

  • Team Training

Ensure that team members who manage GTM are well-trained and aware of best practices.

  • Comprehensive Documentation

Maintain detailed documentation of your GTM setup, including tags, triggers, variables, and data layer structure.

3. Stay Updated

  • Follow GTM Updates

Keep up with updates and new features in GTM to leverage the latest capabilities.

  • Industry Best Practices

Regularly review industry best practices and adjust your GTM setup accordingly.

By following these best practices and regularly auditing your Google Tag Manager setup, you can ensure accurate data collection, optimal performance, and compliance with privacy standards. 

Regular audits help the integrity of your data and improve the efficiency and effectiveness of your marketing efforts.


Google Tag Manager is an indispensable tool for digital marketers, offering flexibility and control over tracking and analytics. 

However, its power comes with the responsibility to ensure the setup is maintained correctly. 

Regular audits, guided by best practices and key performance metrics, are essential for maximizing the benefits of GTM while minimizing potential issues. 

By staying organized, adhering to standards, and continuously monitoring your setup, you can maintain a robust and efficient GTM implementation that supports your marketing goals and business objectives.


Do you like what you read? Learn more about Digital Analytics on our blog here.