What is the XID cookie?
Stores a unique identifier used by Comscore's ScorecardResearch service to measure audience traffic, analyze user interactions, and conduct market research.
Table of Contents
About XID
| Vendor | Comscore |
|---|---|
| Cookie Domain | scorecardresearch.com |
| Category Category The functional category of the technology, such as Web Analytics or Social Media. Learn more | Audience Research & Feedback |
| Consent Category Consent Category The consent category this cookie most commonly falls under across sites we scan, normalized into four standard categories. Learn more | Targeting & Advertising |
| Prevalence | Very Common |
| Popularity Popularity Popularity is calculated from our dataset of 4.5B+ cookies analyzed across hundreds of millions of web pages. Learn more | Found on 10.1% of scanned pages |
| Expiration Type | Timestamp |
| Expiration Duration | 24 days |
| Party Type Party Type Whether the cookie is first-party or third-party. Learn more | 3rd-Party |
| Risk Level Risk Level Rates how sensitive the data stored by this cookie is (High, Medium, or Low) based on data classification and distribution. Learn more | Medium |
| Vendor Privacy Policy | https://www.comscore.com/About/Privacy |
| Vendor Website | https://www.comscore.com |
What is the purpose of XID?
The XID cookie is set by ScorecardResearch (a service of Comscore) web tags. It contains a unique online identifier assigned to a visitor's browser to track their behavior across different websites. The cookie enables Comscore to collect data on internet and electronic network activity, including browsing history, site preferences, and interactions with content and advertisements.
This data helps Comscore generate digital consumption reports and audience measurement statistics for its clients, allowing them to understand demographics and ad campaign reach. In certain instances, advertising networks or advertisers may use ScorecardResearch's services to measure ad effectiveness or for interest-based advertising, and the data linked to this identifier may be shared with third-party service providers as part of these measurement activities.
What are the Privacy Risks of XID?
Risk Level: Medium
The XID cookie assigns a persistent, unique identifier to a visitor's browser, enabling cross-site tracking and behavioral profiling. Although it does not inherently capture directly identifying personal information (such as names or email addresses), it is associated with extensive browsing history, device details, and contextual data. This pseudonymous data may be shared with third-party service providers and used to support interest-based advertising and audience measurement, representing a medium privacy risk due to the user profiling and cross-site tracking involved.
How to Remove XID from a Website
To stop the XID cookie from being set, a website administrator must remove the Comscore / ScorecardResearch tracking tags (for example the comScore Video Metrix or comScore Website Tag, typically loaded from *.scorecardresearch.com) from the site's source code or from the tag management system that injects them. Note that the beacon is frequently bundled inside ad-network code, video players, or publisher toolkits, so administrators may need to inspect network requests to locate where it is being loaded and remove the bundling library or disable the integration that includes it. This identifier is integral to the ScorecardResearch measurement tag and cannot be removed while still running the tag, so removing the vendor's script/integration entirely is the only way to prevent the cookie from being set.