# First-party cookie

> A cookie set by the site the visitor is on, readable only by that site.

Source: https://datacenter.so/glossary/first-party-cookie

A first-party cookie belongs to the domain in the address bar. It is one kind of [first-party data](https://datacenter.so/guides/first-party-data). Analytics and ad tools use them to recognize a returning browser, for example GA4's client id or Meta's `_fbp`.

They are not blocked by browsers the way third-party cookies are, but they are limited. Safari caps cookies set by JavaScript at 7 days ([WebKit](https://webkit.org/blog/8613/intelligent-tracking-prevention-2-1/)), and in the EU, storing a cookie that is not strictly necessary usually needs consent.

## Related terms

- https://datacenter.so/glossary/third-party-cookie
- https://datacenter.so/glossary/itp
- https://datacenter.so/glossary/cookieless-tracking