Multiple GTM Containers & GA4 Configurations On 1 Website

Google Analytics 4 (GA4) and Google Tag Manager (GTM) are powerful tools for managing tracking codes on a website. Sometimes, having multiple GA4 configurations and GTM containers makes sense, but it can lead to several complications and drawbacks as well. Here are several points to consider:

Performance Issues: Each GA4/GTM adds an additional layer of JavaScript to your page, which can impact the load time of that page. Long load times can have serious impacts on user experience, especially on slower networks and/or less powerful devices. These are milliseconds, but milliseconds can add up if your website loads multiple layers of Javascript with each page.

Data Inconsistency: Having multiple GA4 tags can result in inconsistent, conflicting, and redundant data. Each tag, especially if being managed by different parties, could be configured differently or inadvertently duplicated, leading to discrepancies in tracking and reporting. 

Complexity in Configuration: Managing and configuring multiple tags can be complex and creates a higher likelihood of errors. Any changes need to be replicated across each instance, leading to conflicting data.

Increased Server Requests: Each additional tag sends additional server requests, which can strain the server and increase likelihood of hitting API rate limits, particularly in cases where there are strict usage quotas. 

Debugging Challenges: Identifying and resolving issues related to tag firing, variables, and triggers can be more challenging when dealing with multiple containers. 

Potential for Data Leakage: Multiple GTM containers increase the likelihood of unintentional data leakage. If tags from different containers collect similar or overlapping data, it may lead to data integrity issues and violate privacy policies.