Why you need Cookie Keeper
Modern browsers significantly limit cookie lifetime:
- Safari (ITP) — JavaScript cookies max 7 days, 3rd-party blocked
- Firefox (ETP) — a 7-day limit for known trackers
- Chrome — a planned 3rd-party cookie restriction
This means a user who returns after a week is treated as new — and you lose data.
How Cookie Keeper works
- Your sGTM container runs on your own domain (e.g.
track.yourdomain.cz) - Cookies set server-side via the
Set-Cookieheader are treated by the browser as 1st-party - The browser gives them a significantly longer lifetime (up to 2 years)
- Cookie Keeper automatically refreshes and synchronizes the identifiers
Benefits
- More accurate conversion attribution (the user is recognized even after weeks)
- Less user duplication in GA4
- Better data for remarketing
- A higher return on ad investment
Requirements
- The PRO plan or higher — Cookie Keeper is a premium feature
- Your own tracking domain (a verified CNAME)
- A correctly configured sGTM container
Setup
Cookie Keeper activates automatically once all requirements are met. No further configuration is needed — you just need your own domain and a PRO+ plan.