At a glance
Mobile-only CWV pass rate, the percentage of real-user mobile page-loads where all three CWVs (LCP, INP, CLS) met Google’s “good” thresholds simultaneously. The most important CWV view for ecommerce ranking because Google uses mobile-first indexing: mobile CWV is what determines ranking impact for almost all queries. Pairs with crux_desktop_pass for the device split. Mobile typically runs 5-15 percentage points lower pass rate than desktop, reflecting slower mobile networks + mid-tier device CPUs.
| What it counts | (count of mobile page-loads where LCP < 2,500ms AND INP < 200ms AND CLS < 0.1) ÷ (total mobile page-loads in 28-day window) × 100. Same all-three-pass calculation as the headline psi_cwv_pass_rate but filtered to form_factor: PHONE. |
| Sample type | Field data sourced from CrUX. Mobile-only filter applied. |
| Why mobile matters most for ecommerce | (1) Mobile-first indexing: Google primarily evaluates mobile CWV for ranking decisions. Even desktop-search queries are increasingly weighted toward mobile CWV. (2) Traffic share: 60-80 percent of ecommerce traffic is mobile across most verticals. (3) Conversion impact: mobile users are more performance-sensitive than desktop users (smaller screens, slower networks, less patience). |
| Mobile vs desktop gap | Mobile pass rate runs 5-15 percentage points lower than desktop for most sites. Drivers: (a) slower mobile networks (4G + WiFi-throttled vs broadband); (b) slower mobile CPUs (mid-tier Android emulation vs unthrottled desktop); (c) smaller viewports causing different LCP elements to be selected; (d) more mobile-specific JavaScript (touch handlers, mobile menus, responsive widgets). |
| The 75 percent threshold | Google’s CWV ranking signal kicks in at origin pass rate 75 percent or higher (passing) vs below 75 percent (failing). For mobile specifically, this threshold matters most. Brands at 65-74 percent mobile pass rate face mild ranking penalty; brands below 50 percent face significant penalty. |
| Sample size threshold | CrUX requires sufficient mobile traffic (~1,000+ mobile sessions per 28-day window) for stable p75 calculation. Sites with predominantly desktop audiences may have null mobile data. |
| Currency | n/a, this is a percentage. |
| Time window | 28D (CrUX-fixed). |
| Alert trigger | < 75 percent (red, ranking penalty active). Sub-thresholds: amber 75-90 percent, red < 75 percent. |
| Sentiment key | psi_cwv_pass |
| 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 UK-based BigCommerce fashion store, mobile field data Wednesday 15 May 26.| Sub-metric | Mobile p75 | Mobile good % | Drag on all-3 pass |
|---|---|---|---|
| LCP | 4,820ms (poor) | 56% | -23 percentage points |
| INP | 520ms (poor) | 71% | -8 percentage points |
| CLS | 0.170 (needs improvement) | 78% | -5 percentage points |
| All-3 mobile pass rate | 64.8% | (failing band) |
- 64.8 percent mobile pass rate is in the failing band (below 75 percent threshold). Google’s CWV ranking signal is currently treating the site as failing CWV for mobile-search rankings. Competitive ranking positions are being lost on queries where multiple capable competitors pass CWV.
- LCP is the load-bearing problem. 56 percent of mobile users experience LCP under 2,500ms; 44 percent experience it longer. Lifting LCP good-rate from 56 percent to 80 percent would lift the all-3 pass rate by approximately 18 percentage points (from 64.8 → 82-83 percent), crossing the 75 percent ranking threshold comfortably.
- INP at 71 percent good is the second-biggest drag. Improving INP good-rate from 71 percent to 85 percent (achievable via filter-widget refactor + third-party deferral) lifts all-3 pass rate by another 5-7 percentage points.
- CLS at 78 percent good is in band. Some improvement available via aspect-ratio CSS fixes, but lower priority than LCP and INP work.
- The 28-day rolling window means improvements take 28 days to fully reflect. A focused 4-week optimisation cycle lifting LCP + INP + CLS sub-metrics simultaneously can deliver roughly 18-20 percentage point pass rate improvement (64.8 → 84-85 percent) over the 28-day post-fix period. Crosses the 75 percent ranking threshold within the first 14-21 days as the rolling window absorbs.
-
Recommended optimisation sequence for mobile pass rate:
- Week 1-2: Image format conversion + responsive variants (lifts LCP good-rate). Most impactful single fix.
- Week 3: Third-party script deferral + filter widget refactor (lifts INP good-rate).
- Week 4: Aspect-ratio CSS + cookie banner repositioning (lifts CLS good-rate).
- Week 5-8: Field metrics rolling-window absorption; 28-day pass rate fully reflects.
- Commercial impact estimation: lifting from 64.8 percent to 85 percent mobile pass rate restores ranking weight on competitive queries. Estimated organic traffic recovery: 8-15 percent over 60-90 days post-threshold-cross. For a site with 100k monthly mobile organic sessions, that’s 8-15k incremental sessions; at 2 percent conversion at £42 AOV, ~£7-13k monthly revenue recovery.
- Decompose by sub-metric. Identify which CWV is dragging good-rate hardest.
- Apply highest-leverage fix first. Typically LCP via image optimisation; large impact, faster to ship than INP work.
- Plan to the 28-day window. 7-day rolling for early signal; 28-day for full reflection.
- Cross-reference with
crux_desktop_pass. If desktop is also failing, the issues are device-agnostic (server, render-blocking, structural). If only mobile is failing, the issues are mobile-specific (network, mobile JS, mobile media weight).
| Time horizon | Action |
|---|---|
| First 1 hour | Decompose by sub-metric; identify dragging CWV. |
| First week | Apply highest-leverage fix (typically LCP). |
| Day 7 | 7-day rolling shows partial movement. |
| Day 28 | 28-day fully reflects; cross 75 percent threshold. |
| Day 60-90 | Organic traffic recovery shows in GSC reports. |
Sibling cards merchants should reference together
| Card | Why merchants reach for it |
|---|---|
crux_desktop_pass | Desktop pass rate; pair for the device split. |
psi_cwv_pass_rate | Origin-level all-3 pass rate (typically defaults to mobile). |
crux_lcp_p75 | LCP sub-metric; usually the dominant drag. |
crux_inp_p75 | INP sub-metric. |
crux_cls_p75 | CLS sub-metric. |
crux_pass_rate_trend | Pass rate over time; drift detection. |
psi_perf_score_summary | Lab equivalent (mobile profile). |
psi_mobile_vs_desktop_score | Lab device comparison. |
GSC gsc_mobile_usable_pages | Mobile usability ranking signal. |
Reconciling against the vendor’s own dashboard
Where to look:- Google Search Console → Core Web Vitals → Mobile, the canonical view; uses the same CrUX field data.
- PageSpeed Insights, field section showing mobile pass percentage.
- CrUX BigQuery, raw mobile-form-factor data.
| Reason | Direction | What to do |
|---|---|---|
| Window timing. Vortex IQ refreshes daily; CrUX has 1-2 day lag. | Vortex IQ lags | Wait for next refresh. |
| URL grouping. GSC groups URLs by similarity; Vortex IQ shows the origin aggregate. | Different aggregation level | Use the per-URL view for direct comparison. |
Known limitations / merchant FAQs
Why is mobile pass rate so much lower than desktop? Mobile users have slower networks (4G, mobile data) and slower CPUs (mid-tier Android dominates the global mobile mix). The same site that loads fast on a Wi-Fi-connected laptop loads slowly on a 4G-connected phone. Industry-typical: 5-15 percentage point gap between mobile and desktop pass rates. Should I optimise mobile or desktop first? Mobile, almost always. Mobile-first indexing means Google primarily ranks based on mobile CWV. Mobile is also 60-80 percent of ecommerce traffic. Desktop optimisation matters too, but mobile is the priority for ranking impact. Can I have a high mobile pass rate but bad desktop pass rate? Theoretically yes; rarely seen in practice. Desktop is usually faster than mobile because it has fewer constraints (faster network, faster CPU, no battery management). If desktop is failing, the issues are typically server-side (slow TTFB, slow rendering) which affect both devices. My mobile pass rate dropped 10 points overnight. What happened? Possibilities, in order of likelihood. (1) A deploy added new mobile-specific JS (responsive widgets, mobile menu, touch handlers) that’s blocking main thread on mid-tier mobile. (2) A new third-party script (Klaviyo update, GTM tag addition) that runs heavier on mobile. (3) Hero image upload without responsive variants, mobile downloads full-resolution image. (4) CrUX dataset transition: monthly publication boundary may shift the metric. My audience is 80 percent desktop. Should I still care about mobile pass rate? Yes, for ranking. Mobile-first indexing means even desktop search results are influenced by mobile CWV. A site with 80 percent desktop traffic still gets ranked partly on mobile CWV; failing mobile pass rate hurts rankings even when most users are desktop. Can Vortex IQ filter pass rate by URL? Yes; per-URL mobile pass rates appear incrux_origin_vs_url when CrUX URL-level data is available.
Why doesn’t my Catalyst site have a mobile pass rate?
If the site is brand new (under 28 days live), CrUX hasn’t accumulated enough data yet. Wait 28 days post-launch for first CrUX measurement. In the interim, use lab data via psi_cwv_pass_rate (lab measurement on mobile profile).