Despite being known by a handful of names, private browsing mode is generally speaking the same feature that all browsers offer as standard. And if you ever have reason to hide or protect your Internet history from becoming common knowledge, then private browsing mode might sound like a dream come true. Not so fast though because while the private mode does offer a certain degree of enhanced privacy, it's not the all miracle cure that will cover your tracks entirely.
How does regular browsing work?
In a nutshell it alters the way that Firefox operates. But don't be fooled into thinking that it changes anything else. Look at it like this, when you browse the Internet in normal mode, your browser records your browsing history. The sites you visit, and the files you download, are noted and saved in your history. Cookies are also collected and saved. These collect data about you and are meant to enhance your user experience by auto-filling address or payment forms, or login or saved password boxes. Your computer's cache also stores certain aspects of web pages in order to make them load more quickly.
Of course, it doesn't take anyone with a even a passing knowledge of how PCs work to find this stored data. And they don't even need to go into your browsing history - simply starting to type a URL - or website address - into your PC's address bar - will bring up, or suggest, sites starting with the same letter(s) as ones you've searched for, or look at frequently. There is the opportunity to disable some of these functions but your default settings are configured to collect this data.
How does private browsing work?
So, let's say you've switched to private browsing mode. The news you're probably waiting to hear is that now Firefox won't be storing any of this information. Right. None of it: no browsing history, no cookies, no auto-filled data – nothing. Sometimes cookies are kept just while you are using the privacy mode but they will be abandoned once the mode is deactivated. However, it doesn't hide your IP address or your location.
Be aware, however, Firefox that private browsing only works for the web pages that you activate it for. Meaning that if you're looking at Website A in normal mode, and then open Website B and activate private browsing mode, Website A will remain in normal mode.
When is private not so private?
Just because Firefox is no longer able to collect data about your usage in privacy mode, it doesn't mean that any malicious software installed on your PC is powerless too. For example, spyware is known for installing something called a keylogger - a piece of software that can track which keys you type - i.e. the passwords or credit card details you enter and even your personal correspondence. Think private browsing is going to prevent that? Think again. Put simply anyone that has access to your computer can see what you're doing, when you're doing it.
Take parental control software as an example. Private browsing won't help here as apps such as these monitor actual website visits and take screenshots at random. Good news for parents. Bad news for naughty children and curious teenagers everywhere!
Private browsing might stop your browser from storing history on your computer while it's activated but it is not able to instruct other PCs, a server or a router to obliterate your browsing history or hide your IP address. Let's say you've spent the morning at work looking at Twitter - in private browsing mode naturally! When visiting the site, your browsing search is, in effect, leaving your computer and making its way via your company's network and router in order to reach one of Twitter's servers. Meaning that, should your boss pull up data on how employees are using their time, he or she will be able to see your unproductive morning in all its glory.
And you're not safe at home either as search requests still travel via your Internet Service Provider who is able to record traffic data.
The conclusion: private browsing on Firefox can hide your browsing history from people logged into your PC - but that won't prevent it from being visible elsewhere. If you really want to browse the Internet in anonymity you need a VPN as this will go one step further than Private Browsing mode and hide your IP address - from everyone. It also encrypts data and traffic meaning that if you really don't want anyone to know which sites you visit, it's your only option.