In Mixpanel conversion funnels, the First Time Ever Filter can be applied to an event to include only the first instance that a user performs that event. When you use this filter, Mixpanel scans each user’s history to determine if the event is the first occurrence for that user, based on the timestamp.
Interaction with Event Properties:
- When you apply the First Time Ever filter to an event, only the first occurrence of that event per user is included in the funnel.
- If you also filter or break down by an event property, the property value from that first event instance is used.
- If there are multiple events with the same timestamp (e.g., a user performs the event multiple times in the same second), all those events are considered as the “first time” and will match the filter. This means you may see multiple events for a user if you break down by user ID or event property.
Example:
If you have a funnel step for “Purchase” and apply the First Time Ever filter, and then break down by “Product Category,” the funnel will show the product category from the user’s first-ever purchase event. If the user’s first two purchases happened in the same second but with different categories, both will be included.
This filter helps answer questions like:
- Which product category did users purchase first?
- How many users made their first purchase in each category?
For more details, see the documentation on filters and the First Time Ever filter: Mixpanel Reports: Filters
