What are Third Party Cookies?

Third party cookies are cookies that are set by one website, but can be read by another website. Example;cookies are normally set with the same domain as appears in your browsers address bar whereas third party cookies are set with different domains than the one shown on the address bar.

Who uses them?

Some advertisers use these types of cookies to track your visits to the various websites on which they advertise. Most major websites track their visitors' behavior and then sell or provide that information to other companies (like advertisers). Tracking is a term that includes many different methods that websites, advertisers and others use to learn about your web browsing behavior. This includes information about what sites you visit, things you like, dislike and purchase. They often use this information to show ads, products or services specifically targeted to you.

How do they work exactly?

You visit domain www.Interesting.com, the web pages on that domain may feature content from a third party domain. For instance, there may be an advertisement run by www.Advertiser.com showing graphic advert banners. When your web browser asks for the banner image from www.Advertiser.com, that third party domain is allowed to set a cookie. Each domain can only read the cookie it created, so there should be no way of www.Advertiser.com reading the cookie created by www.Interesting.com. So what's the problem?

Some people don't like third party cookies for the following reason: suppose that the majority of sites on the internet have banner adverts from www.Advertiser.com. Now it's possible for the advertiser to use its third party cookie to identify you as you move from one site with its adverts to another site with its adverts.

Even though the advertiser from www.Advertiser.com may not know your name, it can use the random ID number in the cookie to build up an anonymous profile of the sites you visit. Then, when it spots the unique ID in the third party cookie, it can say to itself: "visitor 3E7ETW278UT regularly visits a music site, so show him/her adverts about music and music products".

Privacy Risk

A recent survey in the USA found 84% of people outraged by the idea of advertising companies building up profiles about their browsing habits, even if in some cases the profile might be anonymous? Reports and research on the subject of website tracking tell us that the rejection of third party cookies is growing. Increasing numbers of people are trying to stop and block these third party cookies, or trying to delete their cookies regularly.

The Cookie List


Sometimes known as a transient cookie, stored in temporary memory and remains available for the duration of your active “session” within the browser.

session cookie...


Also known as a stored cookie, it stores a file on your hard drive. The cookie would remain on the hard drive until it reaches its expiration date.

persistent cookie...

Secure & HttpOnly

A secure cookie is just like a regular cookie, except it contains a special ‘HttpOnly’ flag that instructs the browser to restrict access to cookie data.

secure httponly cookie...

third party

Visit a web site, but have a cookie created by a completely different domain. This allows the third party domain to track you i.e. Tracking Cookies

third party Cookie...


Dangerous: Uses various techniques to resists deletion even when you clear your entire history they can remain hidden and reappear like a virus!

Super Cookie...


Dangerous: This is a cookie that can come back to life, hence the name Zombie. After it has been deleted it recreates itself.

Zombie Cookie...


This is an example of a VERY persistent cookie. A cross between Super and Zombie types of cookie.

Ever Cookie...