What is the KRTBCOOKIE_ cookie?
This cookie correlates a PubMatic user ID with partner advertising identifiers to facilitate real-time bidding and targeted advertising.
Table of Contents
About KRTBCOOKIE_
| Vendor | PubMatic |
|---|---|
| Cookie Domain | pubmatic.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 16.7% of scanned pages |
| Expiration Type | Timestamp |
| Expiration Duration | 29 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://pubmatic.com/legal/privacy-policy/ |
| Vendor Website | https://pubmatic.com |
What is the purpose of KRTBCOOKIE_?
The KRTBCOOKIE_* cookie is deployed by PubMatic's supply-side platform (SSP) and advertising technology. The wildcard portion of the cookie name typically represents a specific demand-side platform (DSP) or ad-tech partner identifier (e.g., KRTBCOOKIE_[DSPID]). It stores a correlation string that matches the user's PubMatic ID with the corresponding identity recognized by that partner.
When publisher ad inventory becomes available, PubMatic passes this correlated identifier to the partner in the bid request. This allows the partner to immediately recognize the user, reference their own audience data, and make an informed decision on whether to purchase the ad placement. This synchronization process is a core component of programmatic advertising and cross-site audience retargeting.
What are the Privacy Risks of KRTBCOOKIE_?
Risk Level: Medium
This cookie is classified as Medium risk because it functions as a pseudonymous tracking identifier used for cross-site user profiling and targeted advertising. While it does not directly contain plaintext Personally Identifiable Information (PII) like names or email addresses, the identifier is shared with a vast network of third-party demand-side platforms (DSPs) and data brokers, allowing them to link browsing behaviors across multiple domains and build extensive behavioral profiles.
How to Remove KRTBCOOKIE_ from a Website
To remove this cookie, a website administrator must disable or remove the PubMatic integration from the site's source code or tag management system. If PubMatic is utilized within a header bidding wrapper (such as Prebid.js or PubMatic OpenWrap), the PubMatic adapter or bidder must be removed from the wrapper's configuration. As this cookie is integral to PubMatic's identity synchronization and real-time bidding capabilities, it cannot be selectively disabled while continuing to use the broader PubMatic advertising services.