What is the __atuvc cookie?
__atuvc is an HTTP cookie set by AddThis scripts, a social sharing widget service (share buttons, content recommendation tools) that also included traffic analytics and advertising features. The name most likely stands for "AddThis Unique Visitor Cookie".
It appears on a site when that site embeds an AddThis widget or other third-party scripts relying on AddThis infrastructure. The cookie is set by the addthis.com domain or related subdomains, not directly by the visited site.
What data it stores
__atuvc stores an identifier used to recognize the same visitor across multiple visits and across different websites using AddThis widgets. The exact value format is not officially documented and may vary; no reliable public technical details exist about its internal structure.
Collected data is sent to AddThis/Oracle servers and may be combined with other AddThis cookies (such as __atuvs, uid) to build a cross-site browsing profile of the visitor.
What it is used for
For AddThis, the cookie helped measure unique traffic, analyze how users interact with social sharing buttons, and support behavior-based advertising features.
For the website operator, having the AddThis widget (and this cookie) enabled provided statistics on social content sharing, but also meant tracking data was shared with a third party.
Does it require consent?
__atuvc is classified as a marketing/advertising cookie, since it is used to track visitors across multiple websites. Under the ePrivacy Directive (transposed in Romania via Law 506/2004) and GDPR, this type of cookie requires prior user consent, given explicitly through a consent banner.
- The cookie must not be set before the visitor accepts the "marketing" category.
- Site operators must disclose the cookie (or the AddThis widget, if still used) in their cookie policy.
- Consent must be as easy to withdraw as it was to give.
How to block or delete __atuvc
Visitors can delete or block the cookie manually via browser settings (Chrome, Firefox, Edge, Safari – per-site cookie management), or use tracker-blocking browser extensions.
For site owners who still have AddThis widgets embedded, a CMP such as CookieFix can automatically block the AddThis script from loading until the visitor gives explicit consent for the marketing category, preventing the cookie from being set without authorization.
Note: the AddThis service was officially shut down by Oracle in May 2023, so this cookie should appear increasingly rarely on current websites; its presence often signals outdated, unmaintained code.
Frequently asked questions
Very rarely. AddThis was shut down by Oracle in May 2023 and the script is no longer actively maintained. If it still appears on a site, it likely comes from old, unupdated code.
Yes. As a tracking/marketing cookie, it requires prior consent under GDPR and the ePrivacy rules, and cannot be set automatically when the site loads.
If AddThis widgets are still active on the site, the cookie will be recreated on the next visit, but the site will no longer be able to link the current visit to prior browsing history.
The typically reported duration is about 13 months, though this can vary depending on the specific script configuration implemented on a given site.