How to create a custom event property
How to create a custom event property
How to create a custom event property
Creating a Custom Event Property in Mixpanel
You can create a custom event property directly within a report using the property builder:
Open the property builder — Click the plus (+) button to the right of the search bar in your report, then select "Custom Event Property". [Custom Properties]
Give your property a name — Enter a descriptive name for the new property.
Define the formula — Click the formula bar and write your calculation using Mixpanel's Excel-like formula language:
Press Ctrl + Space to see available functions.
Type a period (.) to browse and select event or user profile properties to include.
Use Insert Example from the dropdown to start with a pre-built use case.
Note: the formula cannot exceed 20,000 characters.
Apply or Save:
Click Apply to use the property locally within the current report only.
Click Save to make it permanently available across all reports and to other project members (Growth and Enterprise plans only).
Use Save and Share to share it with specific colleagues, teams, or your entire organization.
Note: Free plan users can create custom properties locally within a report. Saving globally for reuse requires a Growth or Enterprise plan. [Custom Properties]
Bonus: Borrowed Properties
If you need a property from a prior event to appear on a future event (e.g., using a "Search term" from a "Product Searched" event on a "Purchase Completed" event), you can use the Borrowed Property feature when creating your custom event property. Each project supports up to 20 borrowed properties. [Borrowed Properties]
ℹ️ Tip: Mention @kapa.ai in the thread for follow-ups or DM the app for 1-to-1 help.
A few things to check:
Your role/plan — The ability to create custom properties (beyond saving for self) requires at least an Analyst role. If you're a Consumer, you can only save custom properties for yourself. Verify your project role with your admin. [Roles & Permissions]
Where you're clicking — The plus (+) button for custom properties appears to the right of the property search bar, not the event search bar. Make sure you're in the right context — for example, when adding a breakdown or filter, not when selecting an event metric. [Custom Properties]
Which report you're in — Custom event properties are available in reports like Insights, Funnels, Retention, and Flows. If you're in a different context, the option may not appear.
Beyond that, the knowledge sources don't provide more detail on why "Custom Event Property" might be missing as an option specifically. I'd recommend checking Mixpanel's support or community forums for further troubleshooting if the above doesn't resolve it.
ℹ️ Tip: Mention @kapa.ai in the thread for follow-ups or DM the app for 1-to-1 help.
Based on the knowledge sources, this sounds like you want to use the if function in a Custom Property formula. Here's how:
Basic Syntax
if(condition, value if true, value if false)
Your Example
If you want: "If Property 1 = True, then True":
if(<Property 1> == true, true, false)
More Complex Example with Multiple Conditions
You can chain conditions using and / or:
if(<Property 1> == true and <Property 2> == "some value", true, false)Or use ifs for multiple checks:
ifs(
<Property 1> == true, "Condition A",
<Property 1> == false, "Condition B"
)
Key Notes
Replace <Property 1> with your actual property by typing period (.) in the formula bar to browse and select available properties. [Custom Properties]
The == operator for strings is case-insensitive. [Comparison Operators]
Available constants are true, false, and undefined. [Constants]
Note: Custom Event Properties can reference both event and user profile properties in the formula. Custom Profile Properties can only reference user profile properties. [Custom Properties]
ℹ️ Tip: Mention @kapa.ai in the thread for follow-ups or DM the app for 1-to-1 help.