Speed & Core Web Vitals

Test your site's performance using Google PageSpeed Insights. LCP, INP, CLS, TBT, FCP for both mobile and desktop. Free, ~30 seconds.

Mobile + DesktopLCP / INP / CLSPowered by Google~30 seconds
This tool analyzes the single URL you enter, not your entire website.
Auditing your website…Running PageSpeed Insights for mobile + desktop. This can take 20-40 seconds.

What We Check

Every check comes with a pass/fail result and specific fix instructions.

Mobile Score

Overall Lighthouse performance score for mobile devices. Combines all metrics into one number 0-100. Google ranks mob...

Mobile Lcp

Largest Contentful Paint — when the biggest content element loads. Threshold: 2.5s. Critical for ranking.

Mobile Cls

Cumulative Layout Shift — how much the page jumps around as it loads. Below 0.1 = stable layout.

Mobile Tbt

Total Blocking Time — milliseconds the main thread is blocked. Proxy for INP. Below 200ms = responsive.

Mobile Fcp

First Contentful Paint — when the first text/image appears. Below 1.8s = fast initial paint.

Mobile Si

Speed Index — how quickly content visually populates. Below 3.4s = good visual progress.

Desktop Score

Overall Lighthouse performance score for desktop. Easier to score 90+ on desktop than mobile.

Desktop Lcp

Largest Contentful Paint on desktop. Same 2.5s threshold but desktop typically beats it easily.

Desktop Cls

Cumulative Layout Shift on desktop — should be virtually zero on desktop.

Desktop Tbt

Total Blocking Time on desktop — should be lower than mobile due to faster CPUs.

Desktop Fcp

First Contentful Paint on desktop — should be very fast, often under 1s.

Desktop Si

Speed Index on desktop — usually well under 3s with optimization.

Why It Matters

Numbers that make a difference for your website.

6

Core Metrics

Every CWV that matters

2x

Audits

Mobile + Desktop together

Real

Lighthouse

Google's own engine

30s

Results

Complete in half a minute

Frequently Asked Questions

Common questions about this tool and how to use the results.

What is Core Web Vitals?
Core Web Vitals are Google's key metrics for user experience: LCP (loading), CLS (visual stability), and INP/TBT (interactivity). They directly affect search rankings.
Why does mobile score lower than desktop?
Mobile audits simulate a slower CPU and 4G network, which is how most users actually experience your site.
How is this different from PageSpeed Insights?
We use the same Google API but present results in a cleaner format with pass/fail scoring and specific fix recommendations.
My site scores 100 on desktop but 50 on mobile. Is that normal?
Yes, very common. Mobile tests are much stricter. Focus on optimizing mobile first since Google uses mobile-first indexing.

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