What it is
UET reports conversions and can support remarketing for Microsoft Advertising. It may sit alongside other advertising tags in a container, so consent must be configured for the individual tag rather than inferred from the container.
The catalogue matches bat.bing.com before the general bing.com rule so that UET is reported as the advertising tag it is, rather than as unspecified Microsoft traffic.
What a scan matches
A verification scan drives a real browser and records the outbound requests observed during its configured journeys, so Microsoft Advertising (UET) is identified by request hosts and paths rather than by source-code claims. Requests on unvisited paths, after unperformed interactions or solely on the server remain outside that observation.
- bat.bing.com: the UET endpoint, matched specifically
- bing.com: broader Microsoft advertising
Cookies are classified by name before domain because many analytics and advertising tags write first-party cookies through the page, which places a vendor-related identifier on your domain. Matching known names helps attribute those values without assuming that every first-party cookie came from your own application.
| Cookie | What it is for |
|---|---|
| _uetsid | Session identifier for UET |
| _uetvid | Persistent visitor identifier for UET |
| MUID | Microsoft user identifier, shared across Microsoft properties |
Controlling it with consent
No named adapter. Gate it as a custom script attached to marketing, or as a container tag with a consent setting.
MUID deserves attention in an audit because it is shared across Microsoft properties, which makes it a cross-site identifier rather than a site-scoped one.
No named adapter: choose the appropriate control
The product ships named adapters for Google Tag Manager, Google Analytics, the Meta and TikTok pixels, and Klaviyo. Choose the control route that fits this technology: a custom HTTPS script declaration for a browser loader, an individual consent condition inside a tag manager, a platform or app setting, or a click-to-load placeholder for a frame. Server-side integrations need their own enforcement because a browser runtime cannot stop them.
What breaks if it is refused: Microsoft Advertising conversion measurement and remarketing for refusing visitors.
Verifying it
Before consent there should be no request to bat.bing.com and no _uetsid, _uetvid or MUID. Check that UET has not been added to a container alongside a Google conversion tag with different consent settings.
- Before a choice: optional tracking endpoints and optional identifiers are absent; any intentionally loaded necessary or functional surface matches the control model described above
- After rejecting optional categories: optional activity remains absent and the refusal persists across a reload
- After granting the relevant category: the expected loader or embed appears and the feature behaves normally
- After withdrawing: new optional activity stops; where the vendor supports a consent signal, verify that the signal is sent as well as checking network behavior
Common questions
Is Microsoft Clarity the same thing as UET?
No. Clarity is session recording and heatmaps, classified as analytics; UET is advertising conversion tracking. They are separate products with separate cookies, and a visitor might reasonably treat them differently.
Sources and verification
Verified on . Product-behaviour statements were checked against the current implementation and tests. The links below are the verification basis recorded for this article. They support the stated facts, not a legal conclusion for every site or configuration; recheck changing vendor behaviour before relying on it in production.
- Microsoft Advertising: Universal Event Tracking
Vendor documentation
Checked
See what your own site is loading
A browser scan reports the requests and storage it observed during the sampled journey. Use configured workspace scans to compare the states and pages that matter to your implementation.