How to calculate how much time the user is on a web page?

Question

im making some statistic codes for my website (im a php developper). I want to calculate how many seconds/minutes the web user stay on any page (like google analytics do) but i have no idea of how to make this. Thanks for any help or scripts!

Answer 1

How are you gathering the data? The common options would be instrumenting the page using javascript, looking at webserver log files, in the server-side request handler or sniffing the TCP/IP traffic.

Doing it "like Google Analytics" implies the former. In which case the way to do it would be to grab a timestamp as soon as possible when the page loads (rather than waiting for page ready / onload event) and compare that value with the previous tiestamp (so you'd probably store that in a cookie). Then you need some way to send this back serverside, and a way of recording and reporting on the data.

Note that trying to fire an ajax call as the user leaves the page, e.g. via onunload, will not work reliably (the page launching the request is at the end of its lifecycle). The important thing here is the ASYNCHRONOUS part. And making a synchronous call will just have the effect of slowing down the website.

You might want to have a look at Yahoo Boomerang - although it doesn't support dwell time measurements out of the box, it's easy to extend. For a backend, you could do a lot worse than Graphite

Answer 2

You can fire an unload event in javascript when the user leaves the page, which sends an Ajax request to your server. Since this may not work in all browsers, especially if the network latency is high, also have a ping script (also with Ajax) which calls your statistics system once in a while as long as the user stays on the page (for example, every 10-60 seconds depending on the resolution you want).