What is the TDID cookie?
This cookie stores a pseudonymous device identifier used by The Trade Desk to recognize web browser profiles over time for targeted advertising and cross-site tracking.
Table of Contents
About the TDID cookie
| Vendor | The Trade Desk |
|---|---|
| Cookie Domain | adsrvr.cn,adsrvr.org |
| 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 21.4% 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 | High |
| Vendor Privacy Policy | https://www.thetradedesk.com/legal/privacy |
| Vendor Website | https://www.thetradedesk.com |
What is the purpose of the TDID cookie?
The TDID cookie is an online identifier set by The Trade Desk on its adsrvr.org and adsrvr.cn domains. Its primary purpose is to uniquely identify a user's browser or device across multiple partner websites and ad networks to facilitate cookie syncing, audience mapping, and programmatic ad bidding. This allows demand-side platforms (DSPs), supply-side platforms (SSPs), and data management platforms (DMPs) to match their user IDs to The Trade Desk's identifier, enabling data portability and personalized advertising across the open web.
The value of the cookie is typically a 36-character globally unique identifier (GUID). By maintaining this consistent identifier, The Trade Desk can build and continually update pseudonymous user profiles containing behavioral data, which are then used by advertisers to deliver targeted campaigns, control ad frequency (frequency capping), and measure campaign performance.
What are the Privacy Risks of the TDID cookie?
Risk Level: High
The TDID cookie acts as a persistent, cross-site tracking identifier used extensively within the programmatic advertising ecosystem. It allows The Trade Desk and its partners to compile detailed pseudonymous user profiles spanning multiple domains. Due to its core function of mapping identities across various third-party domains for the purpose of targeted advertising and audience profiling, it poses a significant privacy risk and is heavily scrutinized under frameworks like GDPR and CCPA.
How to Remove the TDID cookie from a Website
To remove this cookie, the website administrator must identify and remove The Trade Desk tracking pixels, sync tags, Universal Pixel, or associated JavaScript files from the website's source code or tag management system. If The Trade Desk is integrated indirectly through a third-party programmatic advertising partner, Supply-Side Platform (SSP), or data management platform (DMP) that syncs data with the adsrvr.org endpoint, the administrator must modify the configuration within those partner platforms to disconnect or pause the data synchronization with The Trade Desk. If The Trade Desk's advertising functionality is required, the cookie cannot be removed without removing or disabling the underlying tag/service that sets it.