Private browsing was introduced to in Firefox 3.5, which allowed users to browse privately without keep the web history. This is quite common feature these days and also servers a very useful purpose. Now it would be interesting to know how people actually use Private browsing in Firefox.. Using the Test Pilot add-on, Mozilla researchers were able to establish that there are a few moments during the day when more people use Private Browsing.

According to Mozilla Blog of Metrics

Private Browsing was introduced in Firefox 3.5, giving users the option of browsing the web without keeping track of their history. A recent Test Pilot study recorded – among other things – the time users activated Private Browsing, and the time they deactivated it. Though what happens in Private Browsing stays in Private Private Browsing – that is, neither Firefox nor Test Pilot records anything during the period – we did learn a few things about timing and duration. Here are a few simple insights we’ve gleaned from the data.

Mozilla highlights the fact that no data was actually recorded during Private Browsing. Test Pilot enables users to combine various experiments and surveys Mozilla is holding. It is completely opt-in and the users are in control of the data collected and submitted.

Further from the study, Mozilla discovered that there are many times during the day when users activate this interesting feature. The first and biggest spike is during the lunch break, between 11 AM and 2 PM, when most people go into Private Browsing.

This makes sense, being at work, users may desire to do a bit of personal browsing during their breaks, for example to check out Facebook and the likes, without leaving too many traces. When they do activate Private Browsing, most people do not use it for that long, 10 minutes seems to be the decent spot. .

The 25th percentile stays on for about 4 and a half minutes, the 75th percentile around 22 minutes, and the median stays in for about 10 minutes. This trend appears to hold over the entire course of the day, with the notable exception of 5pm,” Mozilla explained.