What is the CLID cookie?
CLID is an HTTP cookie set by the Microsoft Clarity script, a free behavioral analytics tool that generates heatmaps and session recordings of website visitors.
It appears in the browser as soon as the Clarity script loads on the page, whether it is added directly by the site administrator or through a tag manager such as Google Tag Manager.
What data it stores
The cookie stores a unique identifier associated with the visitor's browser, used by Clarity to link subsequent sessions to the same user. The exact value format is not publicly documented by Microsoft and may vary.
Data collected through this identifier (interactions, mouse movements, clicks, scrolling) is sent to Microsoft Clarity's servers for processing and displayed in the site's Clarity dashboard.
What it is used for
For the provider (Microsoft), CLID allows behavioral events to be grouped under the same visitor, so heatmap reports and session recordings correctly reflect a user's journey rather than isolated events.
For the site administrator, this means more accurate insights into how visitors interact with pages: where they click, how far they scroll, and where they struggle – information used to improve design and conversions.
Does it require consent?
CLID is classified as a statistics (analytics) cookie. Since it is used to analyze visitor behavior and is not strictly necessary for the site to function, it requires the user's prior consent under the ePrivacy Directive and GDPR.
- The site administrator must disclose this cookie in the cookie policy, under the „statistics” category.
- The Clarity script should only load after the visitor consents to the statistics category, not by default when the page loads.
How to block or delete CLID
A visitor can delete or block this cookie at any time from browser settings (Chrome, Firefox, Edge, Safari), in the per-site cookie management section. Tracking-blocker browser extensions can also prevent it.
For site administrators, the correct approach is not manual deletion but preventing the Clarity script from loading before consent. A CMP such as CookieFix automatically blocks the Microsoft Clarity script until the visitor accepts the statistics category, preventing the CLID cookie from being set without consent.
Frequently asked questions
No, it is a standard analytics cookie used only to recognize returning visitors and generate behavior statistics; it does not affect the functioning of the device or browser.
It is set by the Microsoft Clarity script, installed by the site administrator or via Google Tag Manager, to collect visitor behavior data.
Its typical duration is 1 year from the last interaction, after which the browser removes it automatically unless renewed by a new visit.
Yes, as a statistics cookie it must be listed in the consent banner, and the Clarity script should not load before the visitor accepts this category.