A visitor_id that connects the ad click, the landing page, and the conversion — even when cookies get cleared between steps. First-party, server-side, no consent-banner workaround required.
FOR GROWTH & ATTRIBUTION TEAMS
Safari didn't lose your customers. It lost your ability to see them.
fingerprint.dev recovers the visitor identity that ITP, ATT, and consent banners took away. Join landing-page visits to conversions, dedupe across devices, and stop overpaying for users you already had — without setting a single tracking cookie.
THE PROBLEM
Your dashboards lie. Quietly. Every day.
Third-party cookies are functionally dead in Safari and Firefox. Chrome is phasing them out. iOS 14.5 broke mobile attribution for everyone who isn't Meta. GDPR consent banners give users a one-click way to nuke first-party tracking. The cumulative damage:
- 30–40% of Safari conversions go unattributed in standard GA setups
- Last-click models systematically over-credit direct and branded search
- Paid social ROAS numbers are increasingly fiction
- Cross-device journeys are stitched with hope and a probability model
You're not making bad budget decisions. You're making decisions on bad data.
WHAT YOU GET
A first-party visitor ID that survives the modern browser.
Same user clicks a paid social ad on mobile, then converts via organic on desktop. Without device evidence, those are two users. With fingerprint.dev, they're one — properly attributed.
Pipe visitor IDs into Segment, Snowplow, mParticle, or straight into your warehouse. Join against ad-platform conversion APIs for clean offline attribution.
PATTERNS
Three patterns we see every week.
01 — conversion dedupe
Same user converts twice — once on the first session, once after clearing cookies and returning from a retargeting ad. Visitor ID catches the duplicate before the conversion fires. You stop paying for users you already had.
02 — safari recovery
A user clicks a paid Google ad in Safari, lands, bounces, returns two days later directly, converts. Standard attribution gives 100% credit to Direct. With visitor ID, the original paid touch is preserved server-side and reattributed.
03 — cross-device stitching
Mobile-first journey, desktop conversion. Most models give up. With fingerprint.dev plus a logged-in identifier, you stitch the journey deterministically rather than statistically.
ROI
The math on a typical $1M/month ad spend.
Attribution undercounting in the 25–35% range means roughly $250–350K/month of spend is allocated to the wrong channels. Even a partial fix changes the picture. A 10% improvement in attribution accuracy on $1M/month spend typically yields $30–50K/month of reallocated spend toward actually-performing channels, a 15–20% lift in blended ROAS within a quarter, and cleaner LTV models because cohorts are no longer scrambled by missing touches.
At $199/mo, the question isn't whether it pays for itself. The question is what you've been spending without it.
monthly spend reallocated
$—
— estimated ROAS lift
HOW IT SLOTS IN
Server-side, where your data already lives.
fingerprint.dev fits between your tag manager and your warehouse — or skips both entirely with a server-side call. Common integrations:
- CDPs — Segment, Rudderstack, mParticle (visitor_id as a trait)
- Server-side tracking — GTM Server-side, Stape, Jitsu
- Conversion APIs — Meta CAPI, Google Enhanced Conversions, TikTok Events API
- Warehouses — Snowflake, BigQuery, Redshift (for offline attribution modeling)
// On every pageview, server-side
const fp = await identify({ apiKey: "fp_live_..." });
await segment.track({
visitor_id: fp.visitor_id,
event: "page_viewed",
properties: { utm_source, utm_campaign },
});
PROOF
What growth teams see in the first quarter.
Safari attribution recovery rate, median across pilot customers
lift in blended ROAS after three months of clean attribution data
CAC correction on a previously misattributed channel (real customer, anonymized)
"We were about to cut a channel that turned out to be our second-best performer. Attribution was just broken. fingerprint.dev fixed it in a week."
VP Growth, DTC brand
READY?
You can't optimize what you can't measure.
Free tier gives you 1,000 identify calls — enough to instrument a single landing page and see what your current setup is missing.