What is the _pin_unauth cookie?
_pin_unauth is an HTTP cookie set by Pinterest whenever a page loads a Pinterest-related element: a "Pin it" button, an embedded Pin widget, a Pinterest follow button, or the Pinterest conversion pixel used for ad campaigns.
It appears regardless of whether the visitor has a Pinterest account, hence the name "unauth" (unauthenticated). It is placed by the third-party code on the page, not manually by the site owner, though the site owner remains responsible for disclosing it.
What data it stores
The cookie stores a randomly generated unique identifier that Pinterest uses to recognize the browser on repeat visits, without being tied to a logged-in account. The exact value format is not publicly documented by Pinterest and may vary.
Data gathered through this identifier (pages visited, interactions with Pinterest elements) is sent to Pinterest's servers, which may act as an independent controller for its own advertising purposes.
What it is used for
For Pinterest, _pin_unauth helps build a behavioral profile of non-logged-in visitors, used for ad targeting and for measuring the performance of campaigns run through Pinterest Ads.
For the website hosting the Pinterest element, the cookie indirectly supports conversion reporting (if the site runs Pinterest campaigns) and the correct functioning of social widgets like "Pin it".
Does it require consent?
_pin_unauth is classified as a marketing (advertising/tracking) cookie and is not strictly necessary for the site to function. Under GDPR and the ePrivacy Directive (2002/58/EC, transposed in Romania via Law 506/2004), this type of cookie requires the visitor's prior consent, obtained explicitly through a consent banner.
- The site owner must disclose this cookie in the cookie policy, including provider, category, and duration.
- The script that generates it (Pinterest widget, pixel) must not load before consent is given.
- Refusing consent must effectively prevent it from being set, not just hide a message.
How to block or delete _pin_unauth
A visitor can delete or block this cookie manually through browser settings (Chrome, Firefox, Edge, Safari – per-site cookie management), or use tracker-blocking browser extensions. Browser-level blocking alone won't stop it from reappearing on future visits if the Pinterest element reloads.
For site owners, the correct approach is blocking the script at the source, before consent is given. A CMP such as CookieFix can detect Pinterest widgets and the pixel and automatically block them until the visitor explicitly accepts the marketing category.
Frequently asked questions
No, it's a standard advertising tracking cookie and doesn't contain sensitive data or login credentials. It does raise privacy concerns related to tracking online behavior, though.
Most likely your site includes a "Pin it" button, an embedded Pinterest content widget, or another Pinterest element that sets this cookie automatically.
Yes, as a marketing cookie it requires the visitor's prior consent under GDPR and ePrivacy rules (Law 506/2004 in Romania).
The typical duration is 1 year from when it's set or last updated, though Pinterest may adjust this without public notice.