Cross domain cookies
A click on one domain and a purchase on another, still the same visitor
Free trial. No card, no tag manager.
The journey does not break at the checkout
Many stores sell on one domain and take payment on another. PixelFlow carries its first-party visitor ID from the marketing site to the checkout domain, so the purchase attributes back to the original ad instead of showing up as Direct.
yoursite.com
Click · Buy now
checkout.com
Purchase · $79
_pf_uid a4f9…c2 · same visitor
First-party, not third-party
The cookie is set on your own domain, so it is not blocked the way third-party cookies are.
Attribution survives the hop
Source, campaign and click ID captured on the first domain are still attached when the conversion fires on the second.
Subdomains included
app., shop. and checkout. subdomains share the visitor automatically, with no limit on how many.
Conversion journey
6 touches, 5 days
Facebook Ad
Spring Sale, Video 3
Day 1
Pricing page
pixelflow.so/pricing
Day 1
Direct visit
Returned from bookmark
Day 3
Free trial started
CompleteRegistration
Day 4
Purchase, $79
Growth plan
Day 6
Cross-domain visits appear in one journey
Open the customer journey and you will see the marketing site visit and the checkout visit as steps in the same path, in order, with the time between them.
Better identifiers on the conversion event
Because the visitor is recognised on the checkout domain, the Purchase event carries the click ID and browser ID from the original visit. That raises Event Match Quality on the event Meta cares about most.
yoursite.com · one script
Browser pixel
fbq() in the page
Conversions API
PixelFlow server
Meta · 1 Purchase, same event_id
Connected
2 active
Stripe
Purchase, Subscribe, StartTrial
Calendly
Schedule
Platforms
Webflow
Framer
Squarespace
WordPress
Shopify
+ 9 more
Stripe checkout is covered too
If your checkout is hosted by Stripe, PixelFlow’s Stripe integration matches the payment back to the visitor’s session server-side, so even a fully off-site checkout keeps its attribution.
FAQ
Everything you need to know about tracking across domains.
Which domains does this work across?
Any domains you own that have the PixelFlow script installed. Subdomains of one domain share the visitor automatically.
Do I need to configure anything?
Install the same site script on each domain. PixelFlow handles the visitor ID handoff when a link takes the visitor from one to the other.
Does it work if the checkout is on a platform I do not control?
If you cannot install the script there, use the Stripe or Calendly integration, which match the conversion back to the session server-side.
Is this GDPR compliant?
The cookie is first-party and only set once your visitor has given consent, if you use consent mode.
What is stored in the cookie?
An anonymous visitor ID. No personal data is stored in the cookie itself.
Does it work with iframes?
No. PixelFlow runs in the top-level page and does not track inside cross-origin iframes.
Smarter, server-side tracking
Start sending accurate conversions today - no tag manager, no code, no developer required.
Compatible with
