This guide gathers the most common issues across Calibre's three data sources. Pick the area that matches what you are seeing.
Synthetic testing#
- Tests are failing: See Troubleshoot Failing Tests for the failure codes (authentication errors, timeouts, DNS failures and more) and how to resolve them.
- Metrics or audits are missing: See Troubleshoot Missing Metrics or Audits to understand Standard, Reduced and Minimum audit modes, and why a Performance Score or Total Blocking Time can be absent.
- Results look unstable: See Troubleshoot Test Result Variability for how Calibre re-runs tests and keeps the most representative result.
- Logged-in pages won't test: See Troubleshoot Form Authentication for debugging selectors and login flows.
Chrome User Experience Report#
- No CrUX data for a Site or Page: CrUX only includes pages and origins with enough traffic to be eligible. See the Chrome User Experience Report dataset and Google's eligibility criteria.
- CrUX numbers look stale or updated late: CrUX is a rolling 28-day aggregation, so a recent change takes time to appear. See Why your Synthetic, CrUX and RUM numbers differ.
Real User Monitoring#
- RUM isn't recording sessions: Check your allowed origins and sampling rate, and confirm the snippet is installed, in Install & Configure RUM. Bot detection and excluded regions are covered in Tracking User Performance Data.
- A metric is missing for some sessions: Interaction to Next Paint needs a real interaction, so sessions with no interaction report no INP. See UX Rating for how missing metrics are handled.
Numbers differ between sources#
If Synthetic, CrUX and RUM disagree for the same metric, that is expected: each measures a different population over a different window. See Why your Synthetic, CrUX and RUM numbers differ for the full explanation, and Which data source to use when to pick the right one.
Still stuck?#
Contact our support team and we will help you get to the bottom of it.