Cross-domain vs. additional domains: which do I need?

Usermaven has two related but different concepts: cross-domain tracking and additional domains. They solve different problems, and picking the wrong one is a common cause of split visitor journeys.

Quick comparison

This is the decision most teams get wrong: subdomain splits are a consent-manager problem, not a cross-domain tracking problem.

	Cross-domain tracking	Additional domains
What it does	Carries the anonymous visitor ID from one domain to another via URL parameters	Lets one workspace report on traffic from several separate domains
Use when	A single user journey crosses domains (marketing site → app, or a checkout on another domain)	You own several independent sites and want them in one workspace
Result without it	The same person is counted as two visitors, and the journey splits	You'd need a separate workspace per site

Cross-domain tracking

Use this when the same person moves between two domains as part of one journey — for example yourdomain.com to app.yourdomain.com on a different registrable domain, or a checkout hosted on a payment provider's domain.

Usermaven's cookies don't persist automatically between separate domains (they do between subdomains of the same domain). Cross-domain tracking works by passing the anonymous ID through URL parameters during navigation and restoring it on the destination domain.

Subdomains of the same domain do not need cross-domain tracking — the cookie is already shared. If those are splitting, suspect a consent manager deleting the cookie instead.

Additional domains

Use this when you want one workspace to report on several distinct websites that aren't part of a single funnel — for example a main product site and a separate microsite.

Add the extra domain in your workspace settings, install the tracking script on it, and select it from the domain dropdown in Web Analytics. Each domain reports separately, and you can filter to one at a time.

Choosing correctly

• One journey, two domains → cross-domain tracking.

• Two independent sites, one workspace → additional domains.

• Subdomains of one domain → neither; the cookie already carries. If journeys still split, check your consent manager.

Troubleshooting split journeys

If a visitor still appears twice after setting either option up, the most common cause is a consent manager (such as Cookiebot) deleting the __eventn_id_... cookie on the second domain. See Troubleshoot a cookie consent manager blocking Usermaven.

Related

• Cross-domain tracking — setup steps.

• Identity resolution in Usermaven — how anonymous and identified sessions stitch.