Cross-Platform Tracking

What is Cross-Platform Tracking?


Cross-platform tracking is the practice of measuring the same user’s interactions across multiple platforms—web, mobile web, iOS/Android apps, and even desktop apps—to build one coherent journey. It complements Cross-Device Tracking and Cross-Domain Tracking, focusing on platform boundaries (browser vs. native app) rather than only hardware or domains.

Why it matters
Without unification, you’ll double-count users, fragment funnels, and misattribute conversions. Accurate stitching improves your Attribution Model, clarifies true Conversion Rate, and helps teams see which channels and features drive impact.

How does Cross-Platform Tracking work?

  1. Identity strategy.
  • Deterministic: sign-in based user IDs are the gold standard. When a person logs in on web and app, you attach the same user_id.
  • Probabilistic: fallbacks like device/agent similarity exist but are less reliable and should be minimized.
  1. Identifiers and storage.
  • On web, anonymous identity often starts with a Cookie-backed Client ID.
  • In apps, store an app-scoped ID; when a user authenticates, map both to user_id.
  • Maintain a durable mapping table server-side to reconcile IDs over time.
  1. Event model and sessions.
    Track consistent Event names and properties across platforms (e.g., view_product, add_to_cart). Align Session logic so engagement windows are comparable, and report metrics like Engagement Time uniformly.
  2. Campaign consistency.
    Normalize incoming traffic with the same UTM taxonomy. That ensures platform-agnostic channel/source alignment with Source in reports.
  3. Data routing.
    Use server-side ingestion or event relays to capture both web and app data reliably. This reduces ad-blocker loss on web and SDK drop on mobile.

Privacy & compliance
Obtain consent where required and respect user choice throughout the stitched identity. Align policies and retention with GDPR. Prefer deterministic IDs from explicit logins over opaque device fingerprints.

Implementation checklist

  • Define a canonical user_id and rules for merging anonymous IDs.
  • Standardize event names/props across platforms.
  • Unify sessionization and timeouts.
  • Enforce a shared UTM schema.
  • Validate stitched funnels end-to-end (web → app purchase).
  • Monitor drift with cohort and funnel QA (see Cohort Analysis).