Performance: interactionCount property
The read-only performance.interactionCount property represents the number of real-user interactions that have occurred on the page since it was loaded.
Only discrete interactions with an interactionId — such as clicks and key events — are counted. Other interactions, such as scroll interactions, are excluded.
This is useful when calculating Interaction to Next Paint (INP), and in particular to exclude outliers for long-lived pages. INP takes the 98th percentile of interactions for a page and so excludes 1 in every 50 interactions as "outliers" that are not reflective of overall page responsiveness.
Value
A number, which is initially 0, and increments by 1 with each discrete interaction as measured by PerformanceEventTiming, where an PerformanceEventTiming.interactionId is assigned.
Examples
Checking the number of interactions to accurately calculate INP
For pages with a large number of interactions, you can recalculate INP after excluding 1 out of every 50 outliers using the following pattern:
if (performance.interactionCount >= 50) {
recalculateINP(); // Actual calculation is complex and is not shown here
}
Specifications
| Specification |
|---|
| Event Timing API # dom-performance-interactioncount |