At a glance
CLS (Mobile) is a core web vitals metric tracked from Website Performance (PageSpeed + CrUX) data. It surfaces operational signal at the core web vitals layer so merchants can spot regressions, opportunities, and structural patterns in their store performance. The card pairs with sibling metrics in the Core Web Vitals category to build a complete diagnostic picture; cross-reference the related cards listed below for context.
| What it counts | CLS (Mobile) as exposed by the Website Performance (PageSpeed + CrUX) integration. The metric is computed from the latest available data and refreshed on the standard data refresh. |
| Sample type | Backend API data from Website Performance (PageSpeed + CrUX), refreshed on the standard data refresh. |
| Why it matters | The metric appears in the Core Web Vitals category and complements the sibling cards listed below. Track movement over time to identify regressions or opportunities. |
| Reading the value | Compare the current period to the prior period to identify direction. Cross-reference siblings for the full diagnostic picture. |
| Currency | number |
| Time window | 30D |
| Alert trigger | - |
| Sentiment key | {'type': 'gauge_inverse', 'thresholds': "{'good': 0.1, 'warn': 0.25}"} |
| Roles | owner, marketing, operations |
Calculation
Calculated automatically from your Website Performance (PageSpeed + CrUX) data. See the At a glance summary above for what the metric tracks and the worked example below for a typical reading.Worked example
A representative reading of CLS (Mobile) for a typical merchant on Website Performance (PageSpeed + CrUX). The card reports the current period value alongside a comparison against the previous period. Direction matters: rising values may be healthy or concerning depending on the underlying metric. Cross-reference the siblings below to triangulate cause when the value moves outside expected range. For deeper investigation, use Vortex Mind to trace upstream causes; for natural-language exploration, ask Ask Viq.Sibling cards merchants should reference together
| Card | Why merchants reach for it |
|---|---|
crux_cls_distribution | Core Web Vitals sibling: Layout Shift Distribution. |
crux_cls_p75 | Core Web Vitals sibling: Layout Stability. |
crux_desktop_pass | Core Web Vitals sibling: Desktop Speed Pass Rate. |
crux_fcp_p75 | Core Web Vitals sibling: First Content Visible. |
crux_cls_trend | Historic Trends sibling: Layout Stability Over Time. |
Reconciling against the vendor’s own dashboard
Where to look in Website Performance (PageSpeed + CrUX)‘s own dashboard: The Website Performance (PageSpeed + CrUX) dashboard surfaces this metric (or its components) under the relevant report section. Confirm period boundaries and filter settings match the Vortex IQ profile to reconcile cleanly. Why the Vortex IQ value may legitimately differ:| Reason | Direction | What to do |
|---|---|---|
| Period boundary. Vortex IQ uses 30-day rolling by default; vendor dashboards may use calendar periods. | Variable | Match the period range. |
| Time zone. Vendor uses account time zone; Vortex IQ aligns to merchant reporting time zone. | Marginal | Confirm time zone match. |
| Filter scope. Profile-level filters (channel, B2B, test orders) may narrow the Vortex IQ view. | Variable | Match filter settings. |