Title: Parse.ly’s engaged time heartbeat
Author: staff
Published: July 21, 2022
Last modified: September 24, 2025

---

 1. [User handbook](https://docs.parse.ly/user-handbook/)
 2. [Measuring and reporting performance](https://docs.parse.ly/user-handbook/measuring-reporting-performance/)
 3. [Understanding Parse.ly calculations](https://docs.parse.ly/user-handbook/measuring-reporting-performance/calculations/)
 4. [Engaged minutes](https://docs.parse.ly/user-handbook/measuring-reporting-performance/calculations/engaged-minutes/)
 5. Parse.ly’s engaged time heartbeat

#  Parse.ly’s engaged time heartbeat

Parse.ly measures [engaged time](https://docs.parse.ly/measuring-reporting-performance/calculations/engaged-minutes/)
differently — and more accurately — than most analytics platforms, tracking a “heartbeat”
for each [visitor](https://docs.parse.ly/measuring-reporting-performance/calculations/visitors/)
that’s engaged on your site.

## Traditional time-on-site measurement

Many analytics platforms, including Google Analytics and Adobe Analytics, measure
engaged time based on a visitor’s entry event (when they come to the page) and exit
event (when they leave the page to go to another on your site), both of which come
with a timestamp. From there, these platforms calculate the time delta between each
of those events per visitor session to find time-on-site.

However, this cannot take sessions that do not include an exit event into consideration.
For example, if a visitor comes to your site, then goes to another site or leaves
the tab open, an exit event is never recorded.

Single-page visitors can comprise anywhere from 30-70% of an audience. That’s a 
pretty substantial chunk to leave out of any benchmark analysis of time-on-site.

## Parse.ly’s engaged minutes

To avoid the issue of exit events, Parse.ly uses a [“heartbeat” pixel](https://docs.parse.ly/engaged-time/)
to measure the engaged minutes metric. This pixel pings every several seconds to
check if a visitor is still active on a page:

 1. The browser tab is open.
 2. The user is presently engaging with the page. Parse.ly detects this by identifying
    cursor movement (scrolling, video playing, clicking, etc.).

After five seconds of inactivity, the heartbeat no longer considers the visitor 
engaged, and time stops tracking. Tracking picks up again later if the visitor reengages
with the page.

**Pro Tip**

Note that technical teams need to set the `PARSELY.videoPlaying` value to [track engaged minutes on pages with embedded videos](https://docs.parse.ly/engaged-time/).

Since Parse.ly isn’t dependent on entry/exit events, measuring audience engagement
is more precise. This includes time spent on the final page in a visitor’s session
and single-page visitors. And while heartbeat pixels still technically estimate 
actual time spent, they are markedly more accurate in terms of actual engagement
on the page.

Last updated: September 24, 2025