1. Verify the tag and consent
In plain English: Confirm the intended Measurement ID is present once and allowed to run under the current consent state.
Inspect the page source or tag manager configuration for the correct G- identifier. Check whether the site deliberately blocks analytics until consent. Consent defaults must be established before measurement commands, and updates should reflect the visitor's choice.
- Wrong hostname or production-only guard can suppress local testing.
- A blocker can stop Google tag or collect requests.
2. Inspect browser requests
In plain English: A loaded script is not the same as a successfully sent measurement.
Open DevTools Network, reload, grant consent when appropriate, and filter for googletagmanager, google-analytics or collect requests. Inspect status, Measurement ID and page-location values without exposing private identifiers.
Keep in mind: Test both the initial load and client-side navigation in a single-page application.
3. Check Google tools
In plain English: Use Realtime for recent activity, Tag Assistant for tag behaviour and DebugView for debug-mode events.
Realtime can confirm basic arrival, although processing and report availability are not always immediate. Tag Assistant can identify tags and consent sequencing. DebugView is appropriate when debug mode is enabled and you need event-by-event parameters.
- Open one test page, then navigate to two more.
- Confirm one intended page_view per navigation—not zero or two.
4. Diagnose common failures
In plain English: No data usually has a concrete tag, consent, environment or reporting cause.
Check the Measurement ID, hostname guard, consent choice, blockers, Content Security Policy, duplicate tags and SPA navigation. Verify enhanced measurement configuration before adding manual page views that may duplicate automatic history measurement.
Standard reports can take longer than debugging surfaces. Do not repeatedly reinstall the tag while waiting for processing.
- Missing: no request after consent
- Duplicate: two collect requests for one page view
- Misrouted: request carries the wrong Measurement ID