RankAudit Performance — CrUX Field Data Guide
The Performance tab in RankAudit uses Chrome User Experience Report (CrUX) field data to show real Mobile and Desktop Core Web Vitals — not lab data.
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Introduction
Lab data answers "how fast can this page be?" Field data answers "how fast is this page for real users?" Google ranks on the field data. RankAudit's Performance tab pulls CrUX (Chrome User Experience Report) data and reports the 28-day rolling field metrics for both mobile and desktop. For rankar.ai the report shows "No CrUX data — site may not have enough traffic for the public dataset," and falls back to lab measurements.
The Mobile vs Desktop Split
The tab opens with two summary tiles: Mobile and Desktop, each showing CRUX 28-DAY FIELD and a passing count (e.g. 0/0 passing when no CrUX data is available). The tile in focus is highlighted; click FOCUS → on the other to switch views.
The Detailed Metrics Below
Beneath the tiles: "MOBILE — DETAILED METRICS" with Mobile/Desktop sub-tabs and filter pills (All / Critical / Warnings / Notices). A Push 1 to RankOps button creates tasks for any flagged metrics.
For sites with traffic, this section shows LCP, INP, and CLS as individual metrics with pass/fail badges. For low-traffic sites, the message "No CrUX data" appears with a fallback note explaining the limitation.
What "MOBILE 1P" Means
The label 1P is a per-device label. The Performance tab shows the metric at the page level, the device level, and the 75th percentile of user experience — the threshold Google uses for ranking.
How to Get CrUX Data Flowing
CrUX requires sufficient daily traffic from real Chrome users with Usage Stats enabled. Practical minimums vary, but generally 1,000+ daily page views is the threshold. Until you reach that, your audit will show "No CrUX data" and you should focus on lab-side improvements via the Speed tab.
What's Next
Performance covered. The next article unpacks the Speed tab — full Lighthouse audits with side-by-side competitor comparison.
Apply This With the Rankar Toolkit
RankAudit works best paired with the rest of the Rankar suite. Spin up the relevant tools: RankTalk • RankOps • RankAudit • RankWriter • RankTracker • RankAIO • RankBridge • RankLinks • RankLocal • RankLaunch • RankSpy • RankUX • RankLead. Each module shares data with the others — fewer tabs, one source of truth.