What is the tuuid_lu cookie?
This cookie is used by BidSwitch to store the last update timestamp of a unique visitor ID, facilitating cross-site ad tracking and cookie syncing.
Table of Contents
About the tuuid_lu cookie
| Vendor | BidSwitch |
|---|---|
| Cookie Domain | bidswitch.net |
| Category Category The functional category of the technology, such as Web Analytics or Social Media. Learn more | Advertising & Paid Media |
| 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 15.3% of scanned pages |
| Expiration Type | Timestamp |
| Expiration Duration | 30 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.bidswitch.com/privacy-policy/ |
| Vendor Website | https://www.bidswitch.com/ |
What is the purpose of the tuuid_lu cookie?
The tuuid_lu cookie is a third-party tracking cookie set by BidSwitch, a programmatic advertising infrastructure platform operated by IPONWEB (which Criteo acquired in 2022). It is used in conjunction with the main tuuid cookie, which stores a unique visitor ID. The tuuid_lu cookie (the _lu suffix denoting 'last update') specifically stores a Unix timestamp indicating when the user's ID was last updated or synced. BidSwitch serves as middleware that connects Supply-Side Platforms (SSPs) and Demand-Side Platforms (DSPs), and this cookie helps facilitate cookie syncing (user matching) across the programmatic advertising ecosystem. By keeping track of when the user ID was last synchronized, BidSwitch can optimize ad relevance, frequency capping, and the overall efficiency of real-time bidding (RTB) while avoiding redundant syncing.
What are the Privacy Risks of the tuuid_lu cookie?
Risk Level: Medium
This cookie carries a pseudonymous timestamp used alongside a unique identifier to track users across multiple websites within the BidSwitch programmatic ecosystem. It facilitates behavioral profiling, retargeting, and cookie syncing between various Demand-Side and Supply-Side Platforms. While it does not contain direct Personally Identifiable Information (PII) such as names or emails, its role in cross-site tracking and programmatic advertising presents a moderate privacy risk to users.
How to Remove the tuuid_lu cookie from a Website
To remove the tuuid_lu cookie, website administrators must identify and remove any BidSwitch tags or pixels from their website or tag management system. However, because BidSwitch operates as a middleware exchange connecting various SSPs and DSPs, this cookie is typically dropped indirectly through other programmatic advertising partners (such as Criteo, SSPs, or other ad exchanges) that perform cookie syncing with BidSwitch. Site owners should review their programmatic advertising stack and adjust the configuration or disable cookie-syncing features within those third-party demand- or supply-side platforms. If the cookie is essential for the functionality of the chosen ad network's real-time bidding capabilities, the only way to remove it is to discontinue use of that specific ad partner.