Drawbacks of cookies

Cookies are small text files that websites save on your device. For the person using the device, cookies have several drawbacks.

Storage space

Every cookie takes up a little storage space on your phone, tablet or computer. One cookie is tiny, but a browser that collects them from many sites over months can build up a large number. If the cookies are never deleted, that stored data can slow the device down over time and take up room you need for other files.

Less privacy

Tracking cookies record what you do online: the pages you open, the searches you make and the things you click. That activity can be used to build a picture of your habits and interests, and the picture can be used to target adverts at you. For example, an advertising company can place cookies on both a revision site and a gaming site. Together the cookies show that you have been reading about volcanoes and looking up cheat codes, so a profile of your interests can be built even though you did not choose to share that. Your privacy is reduced because your behaviour is being watched and recorded.

Security risk

Cookies are stored as text files on your hard drive, and other people may be able to access them. If you lend your laptop to someone, or someone else gets into your files, they may be able to read the information a cookie holds. That is the security risk: the file can be read by the wrong person. Cookies are not programs, viruses or malware, so a virus is not the security risk here; the risk is that a stored text file is read by someone it should not be.

Not every problem caused by cookies is a drawback for the user. If visitors keep rejecting cookies and a shop loses the chance to show them adverts, that is a problem for the shop, not a drawback for the user.