Introduction to Event Parameters

What are event parameters, why does Meta require them and what's the difference between standard and custom parameters?

What are Meta Event Parameters?

Event parameters are pieces of information you send along with your events to Meta (via the Pixel or Conversion API). They provide context about what happened, who was involved, and why it matters. For example, if you send a Purchase event, parameters like value, currency, and contents tell Meta the order amount and which products were bought. Without parameters, Meta would know that something happened, but not the important details.

Why does Meta require event parameters?

Meta uses event parameters to:

• Improve attribution accuracy: Parameters like event_time, event_source_url, and user identifiers (such as email or phone) help Meta connect an action on your website with the right ad click or view.

• Optimize ad performance: When Meta knows the value of a purchase or the type of lead submitted, it can adjust bidding strategies and deliver ads to people most likely to convert.

• Match users across devices: Hashed user data (such as email, phone, or external ID) increases the chance that Meta can recognize a customer even if they switched from mobile to desktop. The better the match, the stronger your campaign results.

Standard vs. Custom Parameters

In Meta Events Manager, you will see two types of parameters:

1. Standard Parameters

Predefined fields Meta expects for common event types.

Examples: value, currency, contents (for purchase events), or status (for registration events).

These parameters are automatically recognized by Meta and used directly for optimization and reporting.

2. Custom Parameters

Extra fields you define yourself to capture additional context.

Examples: membership_level, coupon_code, subscription_plan.

Useful when your business needs go beyond Meta’s defaults. While Meta does not optimize directly on custom parameters, you can use them for analysis, breakdowns, or custom audiences.