By default, Matomo (Piwik) will accurately track the time spent on your pages for all pages, except the last page view of the visit. By default, on the last page view of any visit, Matomo counts the “Time spent on page” as 0 second. And when your visitor views only one page in the website, the visit duration will be set to a default of 10 seconds.

-> It is possible to configure Matomo (Piwik) to track the time spent on the page accurately, including the last page view of each visit. Learn more about Accurately measure the time spent on each page in the JavaScript Tracking code guide.