Third-party cookies are cookies set by a domain other than the one the user is visiting. They are typically used by advertising networks to track users across websites.
How do third-party cookies work?
When you visit a website that contains elements from other domains (adverts, social buttons, analytics scripts), those domains can set their own cookies. They can then read these cookies on other websites that include their elements.
Typical uses
- Advertising networks – Tracking users for targeted advertising
- Social networks – "Like" buttons, sharing
- Remarketing – Showing adverts on other websites
- Cross-site tracking – Tracking across websites
The future of third-party cookies
Third-party cookies are under pressure:
- Safari and Firefox already block them
- Chrome is planning restrictions (user choice)
- Privacy Sandbox as an alternative
Legal requirements
Third-party cookies always require explicit consent. They are the most scrutinised by regulators due to their potential for invasive user tracking.