Best Practices for Naming and Registering Custom Parameters in GA4

Best practices for naming and registering custom parameters in GA4 include the following key points:

• Use clear, descriptive, and consistent naming conventions: Parameter names should be lowercase, use underscores instead of spaces, and avoid special characters or abbreviations unless standardized across teams. Names should be meaningful but concise, ideally under 40 characters (e.g., product_color, shipping_method).

• Follow GA4 syntax rules: Parameter names must start with a letter and can include letters, numbers, and underscores. They are case sensitive, so be consistent with casing to avoid duplication or confusion.

• Stay within GA4 limits: GA4 allows up to 25 custom parameters per event (100 for GA4 360 accounts) and a maximum of 50 custom dimensions per property. Parameter values can be up to 100 characters long. Prioritize parameters that impact key metrics like conversions or revenue.

• Register custom parameters as custom dimensions: After creating custom event parameters (often via Google Tag Manager), you must register them in GA4 by adding new custom dimensions in the Admin > Custom Definitions section. This enables reporting and analysis of those parameters.

• Create and maintain a parameter registry: Document all custom parameters with their names, descriptions, expected values, formats, and implementation guidelines. Include examples and maintain version control with changelogs to track updates or deprecations.

• Implement quality controls: Regularly audit parameter usage, verify value formats, ensure consistency across platforms, and use automated testing to catch errors early.

• Leverage recommended parameters when possible: Use GA4’s predefined event parameters (e.g., item_id, currency) to benefit from standardization and built-in reporting, creating custom parameters only when necessary.

These practices help ensure accurate, consistent, and manageable data collection in GA4, facilitating better analysis and decision-making.