Sessions & Visitors

Visitor ID

A visitor is a unique browser. The SDK generates a random visitorId (e.g., v_k8m2p4x9qr) on first load and persists it to localStorage. This ID survives page reloads and browser sessions but is cleared if the user clears browser storage.

Properties

• Format: v_ prefix + 10 random alphanumeric chars
• Storage: localStorage at key {storageKey}:visitor-id
• Lifetime: Persistent until storage is cleared
• Scope: Per-domain (different domains = different visitor IDs)

Session ID

A session is a single period of active engagement. The SDK generates a new sessionId (e.g., s_a3b5c7d9ef) on each page load and rotates it after a configurable timeout.

Properties

• Format: s_ prefix + 10 random alphanumeric chars
• Storage: In-memory only (not persisted)
• Lifetime: Until timeout or page close
• Timeout: 30 minutes of inactivity (configurable via sessionTimeoutMs)

Activity tracking

The SDK listens for these events to determine user activity:

• mousedown
• keydown
• scroll
• touchstart

When any of these fire, the "last activity" timestamp is updated. If no activity occurs for sessionTimeoutMs, the next track() call starts a new session.

Session end

When a session ends (timeout, page hide, or shutdown()), a session_end event is fired with:

{
  "name": "session_end",
  "metadata": {
    "durationMs": 185000,
    "sessionId": "s_a3b5c7d9ef"
  }
}

Dashboard metrics

Privacy considerations

• Visitor IDs are random, not derived from personal data
• No cookies are used — only localStorage
• No fingerprinting techniques
• Users can clear their visitor ID by clearing browser storage
• The SDK respects "Do Not Track" by design — it doesn't use any tracking pixels or third-party services