What is the Gdyn cookie?
Gdyn is an HTTP cookie associated with the audience measurement service run by Gemius, a Polish company specialized in web traffic measurement and visitor behavior analysis, commonly used by online publishers and media platforms.
The cookie is set on the .hit.gemius.pl domain, meaning it originates from a third-party script loaded whenever a site integrates a Gemius tag (such as Gemius Prism or another audience-measurement product). It typically appears on a user's first visit to a site running this tag, shortly after the page loads.
What data it stores
Gdyn is used by the Gemius system to distinguish visitors and track their browsing behavior over the medium-to-long term for statistical purposes. The exact value stored in the cookie is not publicly documented in detail by Gemius; cookies of this kind generally contain a unique identifier generated per visitor, without directly including personal identifiers such as a name or email address.
Data collected through this cookie is sent to Gemius servers (the gemius.pl domain and related subdomains), where it is aggregated into audience and traffic reports provided to client websites and, in some cases, the advertising industry.
What it is used for
The main purpose of the Gdyn cookie is statistical: it helps Gemius and the integrating website count unique visitors, measure visit frequency, and analyze browsing behavior (pages viewed, time spent, navigation path) over an extended period.
For the site operator, this data feeds audience reports used for editorial, content, or commercial decisions — for example, selling ad space based on traffic figures certified by Gemius.
Does it require consent?
On cookiefix.ro, Gdyn is classified under statistics (analytics). Under the GDPR and the ePrivacy Directive (transposed in Romania through Law 506/2004), cookies in this category are not strictly necessary for the site to function, so they require the visitor's prior, explicit consent before being placed.
- The site operator must disclose this cookie in the cookie policy, listing the provider (Gemius), its purpose, and actual duration.
- The Gemius script that sets Gdyn should only load after consent for the statistics category has been obtained, not by default on page load.
- Lacking a prior-blocking mechanism exposes the site to the risk of a complaint to the data protection authority (ANSPDCP in Romania).
How to block or delete Gdyn
A visitor can manually delete or block this cookie through browser settings (Chrome, Firefox, Edge, Safari), either by clearing cookies for that domain or by enabling third-party cookie blocking, which prevents Gemius from setting Gdyn on future visits.
For site operators, proper control isn't about manual deletion but about preventing the Gemius script from loading before consent. A CMP such as CookieFix can automatically block the Gemius script until the visitor explicitly accepts the statistics category, avoiding premature placement of the Gdyn cookie.
Frequently asked questions
It's a statistics cookie set by Gemius, used for audience measurement and traffic analysis on websites that integrate Gemius scripts.
It typically lasts 13 months from being set, after which it expires automatically in the browser.
It doesn't directly contain identifiers like a name or email, but rather an identifier used for traffic statistics; however, as a persistent identifier it still falls under GDPR consent rules.
Yes, since it's a statistics cookie, it requires the visitor's prior consent under GDPR and Law 506/2004, and the Gemius script should be blocked until that consent is given.