Q: For cross-domain tracking I need to add the linker script to both sites, like in UA — right?

Q: For cross-domain tracking I need to add the linker script to both sites, like in UA — right?

A: Outdated — you're about to paste code you don't need. GA4 made this a UI setting.

— Admin → Data Streams → your web stream → Configure tag settings → Configure your domains.
— Add every domain there; GA4 auto-decorates links between them with _gl and stitches the session. No linker snippet, no developer ticket.
— It only works if both domains use the same Measurement ID / data stream.

Leftover UA linker code can even conflict, so remove it.

TL;DR: Cross-domain in GA4 = list domains in the stream UI, not hand-coded linker. Same Measurement ID required.

Got a GA4 question? Drop it 👇