Copy as markdown[View .md](https://docs.funnelfizz.com/concepts/full-funnel-tracking "View the raw markdown for this page")[Open in Claude](https://claude.ai/new?q=Read%20https%3A%2F%2Fdocs.funnelfizz.com%2Fconcepts%2Ffull-funnel-tracking.md%20and%20help%20me%20with%20this%20FunnelFizz%20topic%3A%20Full%20funnel%20tracking "Open this page in Claude with context")[Open in ChatGPT](https://chat.openai.com/?q=Read%20https%3A%2F%2Fdocs.funnelfizz.com%2Fconcepts%2Ffull-funnel-tracking.md%20and%20help%20me%20with%20this%20FunnelFizz%20topic%3A%20Full%20funnel%20tracking "Open this page in ChatGPT with context") # Full funnel tracking The feature that makes everything else work: **following one person from the first time they saw your brand to the day they churned**, across devices, sessions, browsers, and payment events. This page explains the identity model — the mechanism by which an anonymous pageview becomes a named customer. Understanding it helps when you're debugging "why isn't this user showing up in my funnel?" or deciding when to call `identify`. ## The three identities[​](#the-three-identities "Direct link to The three identities") FunnelFizz stitches three kinds of identifiers together: 1. **Visitor ID** (`_fn_vid` cookie) — assigned on first pageview. Permanent per browser. UUID. 2. **User ID** — your own internal ID for the user (however your app names them). Assigned when you call `funnelfizz('identify', { userId })`. 3. **Stripe customer ID** — `cus_...`. Assigned by Stripe when checkout happens. The goal is to link these three together so that a session that started anonymous on mobile can be tied to the desktop purchase three weeks later. ## The stitch[​](#the-stitch "Direct link to The stitch") ``` Day 1: anonymous visitor lands on your site. → _fn_vid cookie = "vid_abc123" (new UUID) → _fn_sid session = "sess_def456" → pageview event recorded, attributed to vid_abc123 Day 2: same visitor, signs up for a trial. → app JS calls: funnelfizz('identify', { userId: 'user_789' }) → VisitorIdentity row written: vid_abc123 → user_789 → all prior events re-attributed to user_789 Day 3: user checks out on Stripe. → Stripe fires checkout.session.completed webhook → FunnelFizz matches customer.email to user_789 → writes journey event: stage=CUSTOMER, visitor=vid_abc123, user=user_789 → stripe_customer_id = "cus_xyz" stored on the profile Day 30: same user, different device (new browser, no cookie). → anonymous pageview → _fn_vid cookie = "vid_new999" → pageview recorded attributed to vid_new999 → NO stitch yet — FunnelFizz doesn't know this is user_789 Day 30 later: user logs in on the new device. → app JS calls: funnelfizz('identify', { userId: 'user_789' }) → VisitorIdentity row written: vid_new999 → user_789 → BOTH vid_abc123 and vid_new999 now point to user_789 → all their events, on both devices, roll up to the same profile ``` ## Keys and cookies[​](#keys-and-cookies "Direct link to Keys and cookies") | Name | Storage | Lifetime | Purpose | | --------- | --------------------- | ------------ | --------------------------------- | | `_fn_vid` | Cookie + localStorage | 365 days | Permanent visitor ID | | `_fn_sid` | sessionStorage | Tab lifetime | Session ID for grouping pageviews | Neither cookie is shared across domains. If your product is split across `marketing.example.com` and `app.example.com`, enable cross-subdomain cookies by setting `cookieDomain: '.example.com'` when you install tracking (see [Features → Providers](https://docs.funnelfizz.com/features/providers.md) for multi-domain setups). ## The `identify` call[​](#the-identify-call "Direct link to the-identify-call") The single most important call in your codebase: ``` funnelfizz('identify', { userId: 'user_789', // your internal user ID — required email: 'sam@example.com', // optional but strongly recommended createdAt: '2026-04-22T...', // optional — helps with cohort analysis plan: 'pro', // optional custom trait }); ``` **Where to call it:** * Right after signup (immediately — even before the first trial starts). * Every page load after login (idempotent, safe to call repeatedly). * After any auth state change (on every re-auth, OAuth callback, etc.). **What *not* to pass:** * Passwords, tokens, credit card info — anything sensitive. * PII you haven't gotten consent to process (in GDPR jurisdictions). ## Cross-device identity[​](#cross-device-identity "Direct link to Cross-device identity") When the same `userId` is seen on two different `_fn_vid` cookies, FunnelFizz merges them — all events roll up to the same user profile, regardless of which device fired them. This is automatic; no extra config. The reverse isn't true: we don't guess that two anonymous visitors on different devices are the same person. If you never call `identify`, anonymous sessions stay separate. This is intentional — cross-device guessing without identity signals is how creepy tracking happens. ## Email handoff (from email campaigns)[​](#email-handoff-from-email-campaigns "Direct link to Email handoff (from email campaigns)") When FunnelFizz sends an email on your behalf, it embeds a signed profile token into every tracked link: ``` https://your-site.com/pricing?fn_ph= ``` When the recipient clicks, the tracking script reads the token on first event, verifies the signature server-side, and stitches the recipient's profile to the landing visitor cookie — so you can track "this trial user clicked our day-5 email and visited pricing," even if they opened the email on a totally new device. The token is stripped from the URL via `history.replaceState` immediately so it doesn't leak to downstream analytics or referrer headers. ## Journey events[​](#journey-events "Direct link to Journey events") Every stage entry and conversion writes a **journey event**: ``` { "funnelId": "funnel_abc", "visitorId": "vid_123", "userId": "user_789", "stageType": "TRIAL", "eventType": "entered", "fromStage": "CONSIDERATION", "metadata": { "method": "stripe_trial", "productId": "prod_xyz" }, "createdAt": "2026-04-22T12:34:56Z" } ``` Unique constraints per (funnel, visitor, stage, eventType) guarantee that a visitor can't enter the same stage twice in the same funnel. Churn events are the exception — a customer can churn only once per funnel (unique on `funnel × visitor × stageType = CUSTOMER × eventType = "churned"`). ## Full journey view[​](#full-journey-view "Direct link to Full journey view") On any profile's detail page, you'll see a chronological timeline: ``` 2026-04-01 12:04 pageview / Reddit 2026-04-01 12:05 pageview /pricing 2026-04-02 09:22 identify user_789 sam@example.com 2026-04-02 09:23 signup (custom event) 2026-04-05 14:10 stripe_checkout cus_xyz → prod_pro $9/mo trial 2026-04-12 22:30 subscription_active paid 2026-05-12 22:30 subscription_canceled churned ``` This is the raw source of truth. Dashboard metrics are aggregations; the journey is the trace. ## Privacy[​](#privacy "Direct link to Privacy") * No third-party tracking. FunnelFizz doesn't sell data to ad networks. * `navigator.doNotTrack` is respected — if the visitor has DNT set, no events are sent. * GDPR / CCPA: you're responsible for consent. If you're using a consent management platform (CMP), defer loading the FunnelFizz snippet until the user grants "analytics" consent. * All tokens in email links are short-lived and single-scoped. * Profile tokens in the URL are HMAC-signed and verified server-side; an attacker can't guess another user's token. See [funnelfizz.com/privacy](https://funnelfizz.com/privacy) for the full policy. *** **Next:** browse the [Features](https://docs.funnelfizz.com/features/providers.md) section for the full details on each feature.