What are website tracking technologies?

Website tracking technologies are tools that can collect, store, access, or transmit information about visits and interactions with a website. They can help measure traffic, record conversions, or recognise a browser across visits. Some can also connect activity across different websites.

Common technologies include:

• Cookies: Store information in a browser, such as a session or tracking identifier.

• Tracking pixels: Send requests to a server to report page views, purchases, or other events.

• Local storage: Keeps data in the browser that website scripts can retrieve.

• Browser fingerprinting: Combines browser and device characteristics to help recognise a visitor.

These methods often work together. For example, a pixel may report a purchase while a cookie supplies an identifier linking it to an earlier visit.

The applicable privacy rules depend on the technology’s operation and purpose. The ICO’s guidance on storage and access technologies explains that these rules extend beyond cookies. A website review should therefore examine both information stored or accessed in the browser and data sent to external services.