> ## Documentation Index > Fetch the complete documentation index at: https://docs.vortexiq.ai/llms.txt > Use this file to discover all available pages before exploring further. # Mobile Speed Pass Rate, Website Performance (PageSpeed + CrUX) > Mobile Speed Pass Rate for Website Performance (PageSpeed + CrUX) stores. Tracked live in Vortex IQ Nerve Centre. How to read it, why it matters, and how t... **Metrics type:** [Supporting Metrics](/nerve-centre/overview#metrics-types-explained) • **Category:** [Website Performance](/nerve-centre/connectors#connectors-by-type) ## 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`](/nerve-centre/kpi-cards/website-performance/desktop-speed-pass-rate) 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`](/nerve-centre/kpi-cards/website-performance/speed-test-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) | What the mobile pass rate is telling us: 1. **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. 2. **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. 3. **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. 4. **CLS at 78 percent good is in band.** Some improvement available via aspect-ratio CSS fixes, but lower priority than LCP and INP work. 5. **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. 6. **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. 7. **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. The diagnostic flow when this card flags failing: 1. **Decompose by sub-metric.** Identify which CWV is dragging good-rate hardest. 2. **Apply highest-leverage fix first.** Typically LCP via image optimisation; large impact, faster to ship than INP work. 3. **Plan to the 28-day window.** 7-day rolling for early signal; 28-day for full reflection. 4. **Cross-reference with [`crux_desktop_pass`](/nerve-centre/kpi-cards/website-performance/desktop-speed-pass-rate).** 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). Rapid-response playbook: | 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`](/nerve-centre/kpi-cards/website-performance/desktop-speed-pass-rate) | Desktop pass rate; pair for the device split. | | [`psi_cwv_pass_rate`](/nerve-centre/kpi-cards/website-performance/speed-test-pass-rate) | Origin-level all-3 pass rate (typically defaults to mobile). | | [`crux_lcp_p75`](/nerve-centre/kpi-cards/website-performance/page-load-speed) | LCP sub-metric; usually the dominant drag. | | [`crux_inp_p75`](/nerve-centre/kpi-cards/website-performance/click-responsiveness) | INP sub-metric. | | [`crux_cls_p75`](/nerve-centre/kpi-cards/website-performance/layout-stability) | CLS sub-metric. | | [`crux_pass_rate_trend`](/nerve-centre/kpi-cards/website-performance/speed-test-pass-rate-over-time) | Pass rate over time; drift detection. | | [`psi_perf_score_summary`](/nerve-centre/kpi-cards/website-performance/performance-score-summary) | Lab equivalent (mobile profile). | | [`psi_mobile_vs_desktop_score`](/nerve-centre/kpi-cards/website-performance/mobile-vs-desktop-score) | Lab device comparison. | | [GSC `gsc_mobile_usable_pages`](/nerve-centre/google_search_console/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](https://search.google.com/search-console)**, the canonical view; uses the same CrUX field data. * **[PageSpeed Insights](https://pagespeed.web.dev)**, field section showing mobile pass percentage. * **[CrUX BigQuery](https://github.com/GoogleChrome/CrUX#crux-on-bigquery)**, raw mobile-form-factor data. **Why the Vortex IQ mobile pass rate may differ from GSC:** | 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. | **Cross-connector reconciliation:** primarily internal (with sister CWV cards and the desktop counterpart). **Quick rule for support tickets:** if a merchant says *"GSC shows 70 percent mobile passing but Vortex IQ shows 65"*, the most common cause is window timing (Vortex IQ lags 1-2 days) or URL grouping differences. Both views use the same underlying CrUX data. ## 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 in [`crux_origin_vs_url`](/nerve-centre/kpi-cards/website-performance/site-wide-vs-page-performance) 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`](/nerve-centre/kpi-cards/website-performance/speed-test-pass-rate) (lab measurement on mobile profile). *** ### Tracked live in Vortex IQ Nerve Centre *Mobile Speed Pass Rate* is one of hundreds of KPI pulses Vortex IQ tracks across Website Performance (PageSpeed + CrUX) and 70+ other ecommerce connectors. Nerve Centre runs the detection layer; Vortex Mind investigates the cause when something moves; Ask Viq lets you interrogate any number in plain English. [Start for free](https://app.vortexiq.ai/login) or [book a demo](https://www.vortexiq.ai/contact-us) to see this metric running on your own data.