This is a measure of words on the page that have remained stationary in the visible area of the page for more than 2 seconds.

Let’s take a long blog post as an example. If the visitor scrolls to the bottom without stopping, it’s pretty clear they haven’t read the content, and those wouldn’t be counted. But if the visitor stops scrolling and keeps an area of the page open for more than 2 seconds, we count the words that are visible on the screen at that time as having been read. This is related to read percentage.