PerformanceContainerTiming: size property
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The size read-only property of the PerformanceContainerTiming interface returns the total area of the container's accumulated painted region, calculated since the container root was registered.
Value
An integer representing a cumulative area in square CSS pixels.
Description
size reflects only the actual painted area within the container, and omits content that was outside the viewport when it was painted.
This differs from intersectionRect, which is a single bounding rectangle and so can include gaps where no painting has occurred.
Paired with intersectionRect, size provides a useful indication of how much of a container has rendered and become visible so far.
It can also be used during debugging to confirm whether a container's content is painting inside the viewport.
For more information, see When are entries generated? in PerformanceContainerTiming.
Examples
See Observing that only visible paints are counted in PerformanceContainerTiming.intersectionRect.
Specifications
| Specification |
|---|
| Container Timing API # dom-performancecontainertiming-size |