Overview
Apple Link Tracking Protection limits cross-domain user tracking by removing selected tracking parameters from URLs. This behavior applies when users interact with links in Apple’s native Mail app, Messages, and in Safari Private Browsing mode.
When enabled, certain URL parameters are stripped automatically before the destination page is loaded. This can affect campaign tracking setups that rely on third-party or cross-domain identifiers embedded in URLs.
How Apple Link Tracking Protection works
With Apple Link Tracking Protection enabled:
Selected URL parameters associated with cross-domain tracking are removed automatically.
The filtering occurs at click time, before the request reaches the destination domain.
Not all URL parameters are affected; only specific identifiers are targeted.
Apple does not publish an official list of all filtered parameters. The set of affected parameters may change over time and is controlled entirely by Apple.
Example
Link without Link Tracking Protection
http://www.demoshop.com?wt_mc=newsletter.846&gclid=ZmDagOPP2MopAFGZLink with Link Tracking Protection applied
http://www.demoshop.com?wt_mc=newsletter.846Impact on Mapp products
Mapp Intelligence
Default campaign parameters used by Mapp Intelligence (such as mc or wt_mc) are not affected.
Campaign tracking based on first-party parameters remains intact.
Custom URL parameters should be reviewed to ensure they are not subject to removal by Link Tracking Protection.
Based on observed behavior, commonly affected parameters include:
gclid (Google Ads)
msclkid (Microsoft Ads)
fbclid (Facebook)
igshid (Instagram)
twclid (X / Twitter)
mc_eid (Mailchimp)
This list is not exhaustive and may change over time.
Mapp Engage
Standard email click tracking is not affected, as Mapp Engage uses redirect-based tracking.
Additional URL parameters added by Engage are currently not removed by Link Tracking Protection.
Recommended best practices
Prefer platform-native or first-party tracking mechanisms over third-party click identifiers.
Avoid relying on URL parameters that are primarily intended for cross-domain user identification.
Review custom campaign parameters regularly, especially when targeting Apple Mail or Safari users.
Design attribution models that do not depend on the availability of fragile URL parameters.
Other environments with similar behavior
Other browsers and platforms apply privacy mechanisms that can also limit the reliability of URL-based tracking parameters.
For example, clients such as Google Chrome and Gmail may apply proxying, caching, or privacy controls that affect how tracking signals are forwarded. While these mechanisms differ from Apple Link Tracking Protection, they reinforce the need for resilient, privacy-aware tracking strategies.
What is not affected
Redirect-based click tracking
Server-side attribution logic
URL parameters not associated with cross-domain tracking