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What Do Our Web Browsers Really Know About Us? Pt 1/2

Posted on May 30, 2016

As we step tentatively closer to a world with cameras in just about everything (Google Glass, anyone?), privacy concerns continue to rise. While the advent of red-light cameras and GPS-enabled cellphones have ushered in an age where our movements in public can be easily tracked, those aren’t the only things to worry about; we also need to consider the trail of digital breadcrumbs created every time we surf the web, whether at home or at the office.

But what do our browsers really know about us? What does it mean to have a computer cluttered with Internet files? Should we be concerned? In order to answer these questions, we need to understand the nature of the private information stored within the web browser files on our computers and how easily accessible it might be to the unscrupulous few.

Internet Clutter & Temporary Files

You may have heard about temporary Internet files, the bits of data left behind on your computer after surfing the web. The average computer is filled with them, detailing juicy tidbits of information on web browsing habits and taking up valuable hard drive space.

Every time we visit a web page, specific data is stored on our hard drives. The idea is that upon our next visit, the website will load up instantaneously because the computer has already cataloged much of the site content.

A Quick Overview of the Info Stored

So, your web browser knows where you’ve been (which you can see for yourself on your browser’s History page). What else? Other information might include:

  • Your geographical location
  • Bookmarks for regularly visited sites
  • Shopping cart information
  • Downloaded files
  • Image and video content
  • Recent Internet searches
  • Logins and passwords
  • (In rare cases) credit card and billing information

That’s a pretty big list of info, so let’s break things down and examine individual items in more detail.

A Closer Examination

History and bookmarks

This one is pretty self-explanatory. History is that list of your browsing activities that you try to hide from your boss, and bookmarks are those handy shortcuts to your favorite web pages. Most web browsers store information on the specific webpages you last visited, which allows you to start exactly where you left off the next time you go to use your browser. Additionally, many browsers store a history of your recent searches, which could definitely spill the beans if you were trying to keep a surprise gift a secret from your spouse or loved ones!


Your browser stores information on files you’ve previously downloaded, which generally contains information such as the address of the website you downloaded from, the date and time of the download, and a link to the downloaded file’s location on your hard drive. Even if you deleted the downloaded file from your computer, your browser would still have a record of the download!


Cookies are very small text-based information files or database entries that enable previously-visited websites to recognize you. A good example is an e-commerce website that remembers the items in your shopping cart, or a website that keeps track of the weather for your favorite cities. Third-party advertisers can make use of cookies to track your web surfing behavior across multiple sites.

Website Icons

Also known as favicons, these are the small (usually branded) icons that appear in your browser address bar or tabs, depending on your browser. This info is stored locally on your computer, and also tends to contain referral URLs to the corresponding sites. It’s possible to get an idea of the websites you’ve visited based upon the stored favicons, even if you’ve deleted your browsing history!

Images & web page previews

Images such as those you may see in digital magazines or blogs can take time to load, especially on slower internet connections. While this is just about bearable the first time you visit a website, you don’t want to sit there tapping your foot every time you visit the same page. Consequently, they’re stored locally for quick access.

Web storage & DOM storage

Sometimes, websites need to store more information than a regular cookie can handle. Web storage and DOM storage work in a similar fashion to cookies, but with a much greater capacity, offering around 1000 times the storage space of regular web cookies. A good example of browser session storage would be when a website autosaves the contents of a text field, so even if you refresh the browser page, you don’t lose any of your writing.

Coming Up In Part 2

The next instalment of our guide explores what all this web data amounts to, and how it can impact your privacy, both online and offline…

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