Last update: 01.08.2020

WHAT ARE COOKIES? WHAT IS A COOKIE?

Cookies are small files that are stored on a user’s computer. They are designed to contain a modest amount of site- and website-specific data and can be accessed by either the web server or the client computer. This allows the server to deliver a page tailored to a specific user, or the page itself may contain a script that contains cookie data and thus can carry information from one visit to the next website (or websites).

ARE COOKIES ENABLED IN MY BROWSER?

To check if your browser is configured to allow cookies, go to Cookie Checker. This page will attempt to create a cookie and report whether it was successful or not.

For information on how to enable or disable cookies, see “Enabling cookies”.

For information about deleting and clearing cookies, see “Deleting Cookies”.

Can I view/view the cookies I have on my computer?

Most browsers have a configuration screen that allows the user to see what cookies have been stored on the computer and optionally delete them. For more information, see the cookie preview page.

Please note that it is not possible for a web page to view cookies set by other sites, as this would be a privacy and security issue.

WHAT’S IN A COOKIE?

Each cookie is effectively a small lookup table containing pairs of (key, data) values ​​– for example (first name, John) (last name, Smith). After the cookie has been read by code on the server or client computer, the data can be retrieved and used to properly personalize the web page.

When are cookies created?

Writing data to a cookie is usually done when a new web page is loaded – for example, after pressing a “Submit” button, the data management page will be responsible for storing the values ​​in a cookie. If the user has chosen to disable cookies, then the write operation will fail, and subsequent sites that rely on the cookie will have to take an implicit action or prompt the user to re-enter the information stored in the cookie.

WHY USE COOKERS?

Cookies are a convenient way to carry information from one session on one website to another, or between sessions on related websites, without having to load a server machine with massive amounts of data storage. Storing data on the server without the use of cookies would also be problematic, as it would be difficult to obtain a specific user’s information without requiring authentication on each visit to the website.

If there is a large amount of information to store, then a cookie can simply be used as a means of identifying a particular user so that additional related information can be looked up in a database on the server. For example, the first time a user visits a site, they may choose a username that is stored in the cookie and then provide data such as password, name, address, preferred font size, page layout, etc. – all this information would be stored in the database using the username as the key. Later, when the site is revisited, the server will read the cookie to find the username and then retrieve all the user information from the database without re-entering it.

HOW LONG DOES A COOKIE LAST?

The expiration time of a cookie can be set when the cookie is created. By default, the cookie is destroyed when the current browser window is closed, but an arbitrary period of time may persist after that.

Who can access cookies?

When a cookie is created, it is possible to control its visibility by setting the “root domain”. It will then be accessible to any URL belonging to that root. For example, the root could be set to “whatarecookies.com” and the cookie would then be available to the sites “www.whatarecookies.com” or “xyz.whatarecookies.com” or “whatarecookies.com”. This can be used to allow related pages to “communicate” with each other. It is not possible to set the root domain to “top level” domains such as “.com” or “.co.uk” as this would allow broad access to the cookie.

By default, cookies are visible to all paths within their domain, but at the time of creation, they can be restricted to a specific subpath – for example “www.whatarecookies.com/images”.

HOW SECURE ARE COOKIES?

There are many concerns about privacy and security on the Internet. Cookies do not, in themselves, pose a threat to privacy, as they can only be used to store information that the user has voluntarily provided or already has with the web server. While this information may be made available to certain third-party websites, it is no worse than storing it in a central database. If you are concerned that the information you provide to a web server will not be considered confidential, then you should ask yourself whether you actually need to provide this information.

WHAT ARE TRACKING COOKIES?

Some commercial sites include embedded advertising that is provided from a third-party site, and such advertisements may store a cookie for that third-party site that contains information provided to them from the containing site – such information may include site names, specific products viewed, pages visited, etc. When the user subsequently visits another site that contains a similar embedded ad from the same third-party site, the advertiser will be able to read the cookie and use it to determine some information about the user’s browsing history.