Scroll depth and time on page

How far down visitors see each page, and how long it is on their screen. On every plan, measured by the same script as the page views: there is nothing to install or turn on.

What is measured

• Scroll depth: how far down the page the bottom of the screen got, as a share of the page's full height. The first screen counts: a page that fits on the screen is 100 %, and a long page left without scrolling is the part of it that was in view.
• Time on page: the seconds the page was visible, that is, the tab was open and in front. Time in another tab, another app or with the screen off does not count. At most 30 minutes per page view.
• Each page view is measured once, and the measurement is sent when the visitor leaves the page, closes the tab or switches away from it. On a single-page site (React, Vue, Next.js…), moving to another page counts as leaving the previous one; a change of address that replaces the current one (history.replaceState) is not a new page view, as for page views, and the page goes on being measured. Coming back to a tab that was already measured does not measure it again.

What the dashboard shows

• The average scroll depth and the average time on page, for the whole site and for each of its top pages.
• Pages measured: how many page views sent a measurement.
• The share of measured pages seen down to at least 25 %, 50 %, 75 % and 100 %.
• Each measurement is matched to a page view by visitor (the same anonymous identifier), page and day (UTC), and at most one measurement counts per page view: sending more for the same page does not change the figures.
• So the filters apply. Those about the visitor (country, device, browser, channel) apply exactly. Those that can differ between two views of the same page on the same day (a campaign, a referrer) match by visitor, page and day too, so a measurement can count with the other view of that page.

Why there are fewer measurements than page views

• Pages that are still open, and pages opened in a background tab and closed without being looked at.
• Some older browsers drop what a page sends while it closes.
• A page left after midnight (UTC) of the day it was opened is not matched to its visit, the same day boundary every visit uses.
• Bots, your excluded IPs and pages, and browsers you told not to count are never measured, just as they are never counted.

Limits

• A page that scrolls inside a box rather than the window itself (some app layouts do) reads as 100 %: the window never moves.
• Time on page counts while the tab is in front, whether or not someone is looking at it. The 30-minute cap keeps a tab left open overnight from distorting the average.

Privacy and your plan

• No cookies and nothing stored in the browser. Each measurement carries the page's path and two numbers, and is tied to the same anonymous, weekly visitor identifier as the page views.
• The dashboard only shows averages and shares; no visitor's pages can be listed.
• Measurements do not count towards your plan's monthly page views, and they are kept as long as the rest of your data: 6 months on Free, 24 on Pro.