Disabling cookies: how to turn off cookies in your browser

The internet’s anonymity is aptly illustrated in the classic cartoon of two dogs seated at a computer, one saying to the other, “On the internet, nobody knows you’re a dog.” Of course, in actuality, everyone who uses the internet leaves a virtual footprint with every click, even if many users aren’t aware of this. For example, cookies are commonly used to store browsing history and record user preferences, making them among the most important tools for data collection on the internet. However, the interests of website visitors aren’t always behind the use of cookies. Since this cached data can often be used and sold for political and business purposes, an increasing number of users choose to disable cookies in their browsers.

Cookies are tiny text files that store information about a user’s behaviour when visiting a website. When opened, a site generates a cookie which is placed in the user’s computer by the browser. This will be available for future repeat visits to the site, allowing the server to recognise the user so that settings can be stored permanently as well as for the placement of personalised advertising.

There are a number of application possibilities for cookies, and the text files also differ from one another. Some cookies are important for a site’s user friendliness and others serve primarily commercial purposes. So, before you start deleting cookies, it helps to know what function they perform to help you decide which are harmless and which are better to block.

So-called persistent cookies are harmless and provide a better user experience. If you change your Yahoo! mail interface colour, the browser stores this information on your computer with the help of a cookie. The browser then later remembers your chosen setting and automatically displays the Yahoo page in the selected colour, thanks to the cookie.

Session cookies are similarly harmless. These store data such as usernames and passwords (in encrypted form) for a shorter time. In online banking, for example, the browser remembers the access data for the duration of the user session but deletes the information from the cookie as soon as the session has ended.

A virtual shopping cart is another classic example of a session cookie. You can load any number of pages on a shopping site and switch from tab to tab – and yet at the end of the session, all your selected products are stored in your shopping cart. However, if you close the website, in most cases the data will be deleted from the shopping cart.

If a cookie is stored on the user’s hard drive to be able to recognise and track it later, this is called cookie tracking. While the user isn’t in any way limited by this kind of data collection – it runs entirely in the background – you can’t be completely sure of what happens to this data. While the use of tracking cookies as instruments of affiliate marketing and web analysis is essentially harmless, there are certainly scenarios in which user information is used beyond its normal purpose or even passed on to third parties. Furthermore, an explicit danger exists from cookies planted by cybercriminals or when distributed by dubious websites whose aim is to collect as much data as possible.

In summary, tracking cookies can be roughly divided into the following three groups:

1. Affiliate

Cookies are important for affiliate marketing, since the affiliate marketer receives a commission for any purchases by users through the referral. Without tracking or tracking cookies, there would be no way of noting the source of the referral, and the affiliate misses out on their commission. The cookie duration – the period in which the cookie is valid – determines how long an affiliate marketer has a recognised role in any transactions. The same applies to identification of the user. Cookie tracking is not only used for affiliate marketing, but also to create user profiles.

2. User profile creation

Companies use cookies to create user profiles in which the user’s browsing behaviour, interests, and preferences are tracked and stored. Such cookies work in tandem with other cookies, allowing them to collect even more user behaviour data across multiple pages. This data is used to analyse more complex patterns in user behaviour and to present targeted personalised ads to the user.

Although cookies are extremely valuable for businesses, advertising agencies, and above all for online shops, there are numerous privacy concerns about cookie tracking.

3. Malicious cookies

Malicious websites can store cookies on your computer and record your internet activity. These text files can also pass any captured data on to third parties, which is what makes them so dangerous. Like all other “harmless” cookies, these cookies are stored on your PC when you visit certain websites. Privacy advocates warn that tracking cookies compromise users’ privacy while the advertising industry makes the argument that all data is collected anonymously, meaning it can’t be identified with a particular individual.

You can protect yourself from these tracking cookies by disabling cookies.

Using the default settings without deleting cookies in Google Chrome or other browsers such as Firefox, Internet Explorer, or Safari makes for an uncomplicated daily network experience, but tracking via cookies is taking place.

Users can change their cookie settings or delete existing cookies (individually or completely). The following options are available in most browsers:

1. Block cookies
2. Block third-party cookies (e.g. banner ads)
3. Obtain permission for each cookie (usually three options: “allow permanently,” “allow for a session,” or “decline”)
4. Delete all cookies when closing the browser

Some browsers also give the user the option to view the data stored in the cookie or to delete individual cookies.

Each set up has advantages and disadvantages: regular requests to a browser regarding whether cookies are allowed can quickly get annoying. For this browser request option, you should be familiar with cookies and the websites that you want to visit in order to know when to allow cookies and when not to. If you disable cookies altogether, some websites will display error messages or be of limited usability, since some pages only operate on an error-free basis when cookies are enabled. Nonetheless, with cookies disabled, you can be certain that your own data is secure.

Partially or completely blocking cookies is slightly different in each browser. To follow, we’ll show you how step by step.

This short video shows you how to delete cookies from the Chrome browser:

Cookie settings can be found via the “Privacy” tab. Use the slider to select a setting. As you toggle the slider, each setting is explained in detail so that you can select how strictly cookies should be blocked. Setting the slider at the top of the bar is how to block all cookies.

In Internet Explorer, “Medium” is the default setting. This setting blocks cookies from third parties that don’t have a compact privacy policy. In addition, the medium setting limits first-party cookies that can use stored information to contact you without your implicit consent. To completely disable cookies in Internet Explorer, set the slider to the top setting “Block All Cookies.”

This short video shows you how to delete cookies from the Firefox browser:

By opening the cookies list you can also choose to delete specific cookies by placing an “x” next to each individual cookie that you want to remove. On the same screen, it’s possible to delete all cookies at once. Look for the “Delete all” button above the list which allows you to remove all cookies with one click.

It’s always advisable to delete cookies after each session if the computer is shared with other users. In Opera, click “Clear browsing data…” in the “Privacy & security” menu.