What is first-party data?
Nicklas Segatz Mortensen · Growth Hacker · Fractional CMO · Meta Ads Nerd · 8 July 2026 · 3 min.
Definition
First-party data is data you collect directly from your own customers and channels — purchases, website behavior, email engagement, contact details — and which you own and control.
Also called: First-party data, 1st party data, Owned data
Sådan virker det
Førstepartsdata er, hvad du selv indsamler direkte fra kunden — køb, adfærd på eget site, kontaktinfo. Modsat tredjepartsdata, der forsvinder med cookie-restriktioner, ejer du den selv. Den er fundamentet under moderne, robust tracking og målretning.
01The asset that doesn't disappear
Third-party data — collected about the user elsewhere and traded across the web — is on its way out as cookie restrictions and privacy law tighten. First-party data is the opposite: it comes directly from your own relationship with the customer, you own it, and it doesn't vanish when a browser kills a cookie.
It's both more resilient and more precise. Clean, consented first-party data drives better segmentation, stronger lookalikes, higher match quality and more accurate measurement. Building and activating it — via server-side tracking, an email list and zero-party collection — is one of the most important investments for a cookieless future.
Frequently asked questions
What's the difference between first-party and third-party data?+
First-party data you collect yourself directly from the customer and own. Third-party data is collected by others and traded across sites — and it's on its way out with cookie restrictions. First-party data is therefore both more resilient and more valuable.
How do I activate my first-party data?+
Via server-side tracking (for better match quality), customer lists for lookalikes and targeting, and segmentation in email/SMS. The cleaner and more consented the data, the better all those activations perform.
Related terms
Glossary
What is zero-party data?
Zero-party data is data the customer proactively and voluntarily shares with you — like preferences, size, goals or birthday — typically via quizzes, profile questions or preference centers.
Read the entry →Glossary
What is cookieless tracking?
“Cookieless” describes a digital landscape where third-party cookies are gone and first-party cookies are restricted — forcing measurement and targeting onto new methods.
Read the entry →Glossary
What is server-side tracking?
Server-side tracking sends conversion events from your own server (e.g. via a server-side Google Tag Manager container and Meta's Conversions API) instead of from the user's browser — so data isn't lost to ad blockers, cookie restrictions and iOS limitations.
Read the entry →
Nicklas Segatz Mortensen
Growth Hacker · Fractional CMO · Meta Ads Nerd at Oaksmond
Growth hacker and fractional CMO with 10+ years' experience and hundreds of millions in managed ad spend behind him. Background from larger Danish and international scale-ups, and from the agency world.
Meet the team →