methodology / Performance / #8

Mobile PageSpeed score + Core Web Vitals (LCP, FCP, CLS)

#8 · Recommended · Web Quality · weighted · Performance · weight 7.1% · impl implemented · method v1.2.0

Web Quality factor

This factor is part of Web Quality — the weighted 0..100 score that sits above Web Standards. Its weight depends on what kind of site is being measured. Web Standards items take priority; this factor only enters the score once Web Standards passes.

Base weight: 1.0 applied to every site type unless overridden below
Why this weight: Mobile PageSpeed reflects how the site performs for the median visitor. Lower for gov/edu where legacy infrastructure is the norm.

Per-site-type overrides

Site type	Weight	Δ vs base
Personal site	0.5	-0.5
Education	0.7	-0.3
Government	0.7	-0.3

Site types not listed inherit the base weight.

Same factor, two depths.

What we measure

How fast your site feels on a mobile phone. Google uses these scores to decide search rankings, and visitors abandon slow sites within 3 seconds.

How to improve your score

Compress images (WebP/AVIF), lazy-load below-fold media, defer non-critical JavaScript, use a CDN.

Facts

Ticket

WEBQ-8

Scoring

Scoring formulas are versioned with the methodology. The current method (v1.2.0) maps raw measurements to pass, warn, fail. Factor weights determine how much each contributes to the composite — see the methodology index for the full table.

Cited by these standards

Standards in the Standards Library whose satisfiedBy requirement tree references this factor. Each link goes to the standard's full entry — methodology, scope, and the other factors it relies on.

Core Web Vitals Performance global Google's three-metric performance bar: LCP, INP, CLS. Affects rankings and is the closest thing to a universal performance standard.
Largest Contentful Paint (LCP) Performance global Time until the largest above-fold element renders — usually the hero image or H1. ≤2.5s at the 75th percentile is the `good` threshold; >4s is poor.
Mobile viewport meta tag SEO global `<meta name="viewport" content="width=device-width, initial-scale=1">` — one line that decides whether your site is usable on a phone. Mobile-first indexing means without it you don't rank.
Resource hints (preconnect / preload / prefetch / dns-prefetch) Performance global Tell the browser which connections, fonts, scripts, and next-pages it should warm up before they're strictly needed. Single-digit-percent LCP improvements per hint, multiplied across a page.
Speed Index Performance global Average time at which visible parts of the page are displayed, computed from a frame-by-frame video of the load. Captures `feels fast` better than any single milestone metric.

Version history

Version	Change	Date
v1.2.0	Factor introduced. Status: live. Scoring impl: implemented.	2026-04-25

← back to methodology