Scanverra
Performance Audit

A real Lighthouse lab run, desktop and mobile

LCP, CLS, TBT, Speed Index, and TTFB, measured on both a desktop profile and a 375px mobile viewport - with fixes written for the framework Scanverra detects on your page.

Run free performance audit

Every metric, measured

The six signals that make up your performance score.

Largest Contentful Paint (LCP)

How long the biggest visible element takes to render. Google's Core Web Vital for loading speed.

Cumulative Layout Shift (CLS)

How much visible content jumps around as the page loads. Scored directly from Lighthouse's numeric CLS value.

Total Blocking Time (TBT)

How long the main thread is blocked by JavaScript during load - the lab-measurable proxy for real-world interaction delay.

Time to First Byte (TTFB)

How long the server takes to respond before any rendering can start - a server/hosting/CDN signal, not a frontend one.

Speed Index

How quickly the page's content is visually populated, frame by frame, not just when it finishes.

Render-blocking resources

CSS and synchronous scripts that delay first paint, flagged individually so you know exactly what to defer or inline.

How it works

Two full passes, one scan.

Desktop pass

A full Lighthouse run under desktop network and CPU conditions.

Mobile pass

The same page, re-tested at a 375px viewport with throttled conditions - mobile and desktop scores often diverge significantly.

Framework-aware fixes

Scanverra detects your stack first, so a Next.js site gets next/image and priority-loading guidance, not generic "optimize your images" advice.

FAQ

Frequently asked questions

Is this lab data or real-user (field) data?

Lab data by default - a controlled, repeatable Lighthouse run on Scanverra's own infrastructure. When available, a PageSpeed Insights fallback layer can add real Chrome User Experience Report (CrUX) field data alongside it, so you can compare a controlled test against how real visitors actually experienced your site.

Why do my desktop and mobile scores differ so much?

Different network and CPU throttling profiles, plus a narrower 375px viewport that can trigger layout issues invisible on desktop. A site heavy on unoptimized images or third-party scripts typically loses more points on mobile.

Does a 100 performance score mean my site is fully optimized?

It means the specific metrics Lighthouse measures are in good shape on the tested page, under the tested conditions. It doesn't cover every possible performance factor (e.g. server response time under real load, CDN edge coverage) - treat it as a strong signal, not an absolute guarantee.

Can I test more than one page?

Yes - run the audit again with a different URL. Each scan is independent, so you can spot-check your homepage, a product page, and a blog post separately rather than assuming one page represents the whole site.

Free - no sign-up required

Run a free performance audit

Desktop and mobile, every Core Web Vital, with framework-aware fixes.

Run free audit