How they work
The name comes from one-pixel image beacons, but current implementations may use a JavaScript SDK, image request, browser API or server-side event path. A browser SDK can set an identifier and send events such as page views, cart additions or purchases; server-side paths are not visible to a browser-only scan.
Advertising vendors can receive events from many sites and may correlate them using cookie, click, account and other available identifiers. Whether a particular deployment creates cross-site or cross-context profiling depends on its data flow and vendor configuration; the possibility is why advertising pixels require purpose-specific review rather than a harmless “page counter” label.
Controlling one properly
- 1
Have exactly one installation
A pixel may be installed through theme code, a tag manager, a plugin or app, or more than one of those paths. Inventory and remove duplicates before configuring a managed loader, because gating one path does not control another.
- 2
Let the runtime own the loader
Enter the pixel ID in the property configuration. The managed loader is withheld until the marketing category is granted.
- 3
Handle withdrawal
The adapter sends the vendor revoke signal, including to a script that finishes loading after the withdrawal.
- 4
Remember the server side
A conversions API integration runs on your servers and is not controlled by anything in the page. It needs its own lawful-basis, transparency and preference-enforcement design, including a way to honour applicable refusal or withdrawal signals.
Common questions
Do pixels count as a sale under US state law?
They can constitute sharing for cross-context behavioural advertising in California, depending on the data flow, purpose, contracts and exceptions. StrongPrivacy conservatively disables every optional category when GPC applies under an opt-out model so a sale/share use is not missed because it was assigned a different category label.
Can a pixel be blocked without breaking the site?
An advertising pixel should not be required to render or operate the requested page. Test the actual site, however: poorly coupled implementations can attach unrelated functionality to a pixel callback, and that dependency should be separated rather than assumed away.
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.
- ICO: guidance on storage and access technologies
Regulator guidance
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.