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Free PageSpeed & Lighthouse Audit Tool

Run one Lighthouse lab audit to inspect performance, accessibility, best-practices and SEO scores, lab timing metrics and prioritized diagnostics.

Also known as: PSI, PageSpeed Insights, Lighthouse score

Evidence shown with sourceNo account requiredNo invented metrics

Run a real check above

Submit a public URL, domain, or keyword. Novaverb will show only the evidence this tool can actually retrieve or measure.

Evidence model

Know what the result proves

This check proves what one Lighthouse run scored on one simulated device and network, together with its lab timing metrics and top diagnostics. Lab results vary between runs by design. INP is shown only when the accompanying field dataset has enough real-user observations.

1. Source

A live Lighthouse lab audit. The result identifies where its evidence came from.

2. Boundary

Scores come from a single Lighthouse lab audit in a simulated environment. Lab results are a diagnostic and can differ from real-user field data.

3. Next action

Use the finding to verify a problem, then connect a workspace when you need history, monitoring, or site-wide analysis.

PageSpeed explained

Lighthouse scores are a diagnostic, not the ranking itself

A Lighthouse audit runs the page in a controlled lab and grades four categories from 0 to 100. It's the fastest way to find what's slowing a page down and get concrete opportunities - but Google ranks on real-user field data, so treat the lab score as a to-do list, not the verdict.

The four categories

Performance - loading speed and responsiveness from lab metrics like LCP, TBT and CLS.
Accessibility - automated checks for contrast, labels, and assistive-tech support.
Best Practices - security, correct image sizing, and modern web standards.
SEO - crawlable, mobile-friendly, correctly tagged pages.

Lab vs field

Lab data is reproducible and great for debugging. Field data (Core Web Vitals) reflects real users on real devices and networks. Use both: fix in the lab, confirm in the field.

Get the right answer

What to submit - and what to avoid

Submit the page address you want audited. A page behind a login, a paywall or a geographic block cannot be audited because the analyser reaches it as an anonymous visitor. Treating a single run's score as a stable number is the misreading to avoid; run it twice before you act on a difference.

Use it like this

yourdomain.comAny address form works - Lighthouse loads it in a controlled lab. http or https, with or without www, a bare domain or a full path - we normalize it for you.

https://www.yourdomain.com/pageA specific public page is fine; we audit exactly what you submit.

Avoid this

A page behind a login or paywallThe lab run cannot reach authenticated content, so the audit would not represent it.

Public methodology

Exactly how this result is produced

The address is normalized and run through a Lighthouse audit. Category scores, lab LCP, CLS, FCP and TTFB, and the returned diagnostics are reported without re-weighting. INP remains separately labeled as field data when it is available.

We normalize the address and run the URL through Google's Lighthouse audit via PageSpeed Insights.
We report the category scores, lab timings and diagnostics from that run, with field INP labeled separately when available.
We surface the top opportunities Lighthouse identifies, using its published scoring methodology.

Built on public standards

The international standards this check applies

Google's Lighthouse documentation defines the audits, the weightings and the scoring curve, and the PageSpeed Insights documentation defines how a lab run is produced and how it differs from field data. Both are reported as published, so a score here can be reproduced against Google's own tool rather than only against ours.

GoogleLighthouse

Lighthouse audit engine

Runs the open-source Lighthouse audit and reports its category scores.

Read the specification

GooglePageSpeed

PageSpeed Insights methodology

Uses the PageSpeed scoring methodology and keeps lab timings separate from available field data.

Read the specification

We list a standard only where this tool genuinely reads or measures against it. Where a signal is outside a live check, the result says so instead of implying coverage.

Common questions

PageSpeed Checker FAQ

What does the PageSpeed Checker report?

It runs one Lighthouse lab audit in a simulated environment and reports category scores, lab timing metrics and prioritized diagnostics. Field INP appears only when enough real-user data is available.

What is a good Lighthouse performance score?

Lighthouse scores run from 0 to 100. Broadly, 90 and above is good, 50 to 89 needs improvement, and below 50 is poor. Treat it as lab guidance, not a real-user guarantee.

Why do lab results differ from real-user field data?

Lighthouse runs one audit under simulated network and device conditions, so it may not match real visitors' varied hardware and connections. Lab data is reproducible and diagnostic; field data reflects actual user experience over time.

How do I fix the opportunities PageSpeed reports?

Work through the listed opportunities, commonly compressing and sizing images, deferring unused scripts, eliminating render-blocking resources, and enabling caching. Each opportunity estimates potential savings, so prioritize the ones with the largest estimated time reduction.

What is the difference between the PageSpeed and Core Web Vitals checkers?

PageSpeed runs a Lighthouse lab audit with simulated conditions and diagnostic opportunities. The Core Web Vitals Checker reports real-user field data at the 75th percentile. Use lab to diagnose, field to judge actual experience.

Which metrics are lab and which are field data?

LCP, CLS, FCP and TTFB on this panel come from the single simulated audit. INP is not produced by that lab run; it appears only when the accompanying field dataset has enough real-user observations.

Why does my score change between runs?

Lighthouse simulates a run each time, so variability in network modeling, server response and page scripts shifts scores. Run several audits and look at the trend rather than treating one number as absolute.

Does the accessibility score mean my site is fully accessible?

No. Lighthouse checks automatable accessibility issues only and cannot verify everything, like meaningful alt text or keyboard flows. A high score is a helpful baseline, not proof of full accessibility compliance.

Why run a PageSpeed audit?

A lab audit exposes reproducible loading, accessibility and implementation diagnostics. Use it to find technical work, then verify the outcome with field data; one lab run does not predict rankings or every visitor's experience.

Can one PageSpeed audit tell me how all my users experience the page?

No. It is one lab audit in a simulated environment representing a single test condition. To understand real visitors across devices and networks, pair it with real-user field data from the Core Web Vitals Checker.

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