Get your Performance Score, Core Web Vitals, and plain-English fix instructions in 15–30 seconds. Mobile + desktop. No login needed.
Powered by Google PageSpeed Insights — tests mobile & desktop simultaneously. Takes 15–30 seconds.
Paste any publicly accessible URL. The tool runs a full Google Lighthouse audit via the PageSpeed Insights API for both mobile and desktop simultaneously. This takes 15–30 seconds because Google fetches and renders your actual page.
The Performance Score (0–100) measures loading experience. The Structure Score reflects how well your page is built for performance — passing best-practice audits. Both are shown for mobile and desktop. Mobile is the SEO-critical score as Google uses mobile-first indexing.
LCP, CLS and TBT (proxy for INP) are Google's ranking signals. Each shows pass, warn or fail with the threshold. The Browser Timings section adds TTFB, connection time, DOM loaded and fully loaded — the same milestones GTmetrix shows in its Performance tab.
The Structure Audits table lists every issue ranked by impact, with which metric it affects (FCP/LCP/TBT/CLS). Click any issue to expand plain-English fix instructions — including WordPress-specific solutions with the exact plugins and settings to use.
Every metric that matters, explained in plain English with clear thresholds
Most speed tools give you a score and leave you guessing about what it means. This tool gives you every metric that matters explained in plain English so you know exactly what you are looking at and what to do about it.
The Performance Score (0–100) measures how fast your page actually loads for real users. The Structure Score measures how well your page is built for performance, based on best-practice audits like caching, image optimisation, and avoiding render-blocking code. A page can have a high Structure Score but slow Performance if the hosting is poor. You need both to be high.
Core Web Vitals are the three metrics Google uses as direct ranking signals. LCP measures how quickly the main content appears. CLS measures whether elements jump around as the page loads. INP measures how responsive the page is to user clicks. This tool shows all three with a clear pass, warn, or fail status against Google’s exact thresholds.
The Structure Audits section lists every issue found on your page, ranked by impact level: High, Medium, or Low. Each issue shows which Core Web Vital it affects. Click any audit row to expand plain-English fix instructions, including WordPress-specific solutions with the exact plugins and settings to use. No other free tool gives you this level of actionable detail.
Why a slow page costs you positions even when your content is excellent
Google has been clear: page experience is a ranking factor. The Page Experience update rolled out in 2021 made Core Web Vitals an official part of Google’s ranking algorithm. Pages that pass all three Core Web Vitals thresholds at the 75th percentile of real users receive a ranking boost in mobile search, and mobile search is where the majority of Google’s traffic comes from.
Beyond the direct ranking signal, speed affects the indirect signals Google watches closely. A slow page increases bounce rate as visitors leave before engaging. Higher bounce rate tells Google the page was not useful. Lower dwell time signals the same thing. Both reduce your rankings over time, regardless of how good your content is.
TTFB deserves special attention here. It is the foundation of every other metric. Nothing can load until the server sends the first byte. A TTFB above 800ms almost always indicates slow hosting or a lack of server-side caching. Fixing TTFB is consistently the single highest-impact change you can make to your site’s speed and, as a result, its rankings.
Any publicly accessible URL works, regardless of how your site is built
This tool tests any publicly accessible URL. It does not matter what platform, CMS, or framework your website is built on. Paste the URL and get your full speed report.
For WordPress sites specifically, the fix instructions in the Structure Audits go one step further. They include WordPress-specific solutions for every issue, naming the exact caching plugins, image optimisation plugins, and settings to use. If you are on WordPress, you will leave this tool knowing not just what is wrong but exactly which plugin to install and which setting to turn on.
For Shopify stores, the tool identifies which third-party apps or scripts are slowing down your storefront, what your Core Web Vitals score is, and whether your product images are optimised. Shopify’s theme ecosystem frequently introduces performance issues that are invisible without a proper audit. This tool surfaces all of them.
You can also use the Bulk test feature to check up to 10 URLs at once, useful for comparing different page types on your site, auditing a client’s website, or benchmarking competitors in your niche.
How the most popular free website speed test tools compare feature by feature
All four tools measure website speed, but they serve very different purposes. GTmetrix and Pingdom are popular for their waterfall charts and historical tracking. Google PageSpeed Insights gives you the official Lighthouse score. Visiblytics is built around one thing the others skip entirely: telling you exactly what to fix and how to fix it, without paying for a premium plan or knowing how to read a technical audit.
| Feature | Visiblytics | GTmetrix | Pingdom | Google PSI |
|---|---|---|---|---|
| Powered by | Google Lighthouse | Lighthouse + WebPageTest | Custom engine | Google Lighthouse |
| Performance Score | ✓ Mobile + Desktop | ✓ Desktop only (free) | ~ Performance grade | ✓ Mobile + Desktop |
| Core Web Vitals | ✓ Pass / Warn / Fail | ✓ Shown | ✗ Not shown | ✓ Shown |
| Structure Score | ✓ Dedicated score | ✓ Structure tab | ✗ Not available | ✗ Not shown |
| Plain-English fixes | ✓ Every audit | ~ Basic only | ~ Basic only | ~ Generic recommendations only |
| WordPress fixes | ✓ Plugin + settings | ✗ Not provided | ✗ Not provided | ✗ Not provided |
| Mobile + Desktop | ✓ Both at once | ✗ One at a time | ✗ Desktop only | ✗ One at a time |
| Bulk URL testing | ✓ 10 URLs free | ✗ Paid only | ✗ Not available | ✗ One at a time |
| CSV export | ✓ Free, one click | ✗ Paid only | ✗ Not available | ✗ Not available |
| CrUX field data | ✓ Included | ✓ Included | ✗ Not available | ✓ Included |
| No account needed | ✓ Fully free | ~ Free tier limits | ~ Free tier limits | ✓ Fully free |
GTmetrix is excellent for developers who need waterfall charts and historical tracking. Pingdom is useful for uptime monitoring alongside speed. Google PSI is the authoritative source for Lighthouse scores. Visiblytics is the right choice when you want to know not just your score, but exactly what is causing it and how to fix it especially on WordPress or Shopify.
Every other tool tells you what is broken. Visiblytics is the only free tool that tells you how to fix it, with WordPress-specific steps and plugin recommendations for every single audit.
The direct connection between page speed, user experience, and Google rankings
Website speed is the time it takes for your page to fully load and become usable for a visitor. It is not just one number. It is a combination of server response time, how efficiently your page is built, how large your files are, and how the browser processes everything to render the final result on screen.
Speed has a direct and measurable impact on three things that every website owner cares about: search rankings, user experience, and conversions. Google officially uses page speed as a ranking factor and since 2021, Core Web Vitals (Read full guide on Core Web Vitals) have been part of Google’s ranking algorithm. A slow website does not just frustrate visitors, it actively costs you positions in search results.
Running a regular website speed test is not a one-time task. Your site’s performance changes every time you install a new plugin, upload images, add a tracking script, or your hosting environment changes. Checking your speed regularly and knowing exactly what to fix is one of the most impactful things you can do for your site’s SEO and user experience.
A low Performance Score is rarely just a speed problem. It is usually a symptom of deeper technical SEO issues slow hosting, unoptimised images, render-blocking scripts, or a poorly configured CMS. Fixing these properly requires more than installing a caching plugin.
Google Lighthouse scores range from 0–100. 90–100 is Good (green) — passes Core Web Vitals. 50–89 is Needs Improvement (orange). 0–49 is Poor (red). Aim for 90+ on mobile, as Google uses mobile-first indexing for rankings. Desktop scores are typically 10–20 points higher because the test simulates faster network and CPU.
The Structure Score reflects how well your page is built for optimal performance — based on best-practice audits like caching, image optimisation, compression and avoiding render-blocking resources. Unlike the Performance Score which measures raw speed, the Structure Score measures whether your page is configured correctly. A high Structure Score with a lower Performance Score usually means your hosting or server is the bottleneck.
Core Web Vitals are three metrics Google uses as direct ranking signals since 2021. LCP (Largest Contentful Paint) measures how quickly the main content loads — good is under 2.5s. CLS (Cumulative Layout Shift) measures visual stability — good is under 0.1. INP (Interaction to Next Paint) replaced FID as a Core Web Vital in March 2024 and measures responsiveness to user input — good is under 200ms. Pages passing all three at the 75th percentile of real users receive a ranking boost in mobile search. TBT (Total Blocking Time) is a lab-based proxy for INP used by Lighthouse/PSI — it correlates strongly with INP but is not itself a ranking signal.
TTFB (Time to First Byte) is the time between the browser requesting a page and receiving the first byte of the server response. It is the foundation of every other metric — nothing can load until the first byte arrives. Google recommends TTFB under 800ms. A high TTFB almost always means slow hosting, no server-side caching, or a heavy CMS generating pages dynamically on every request. Fixing TTFB with a caching plugin (WP Rocket, LiteSpeed Cache) or upgrading hosting is usually the highest-impact single change.
LCP (Largest Contentful Paint) is usually caused by: a slow server (high TTFB delays everything), a render-blocking resource preventing rendering, a large unpreloaded hero image, or client-side rendering where the main content is injected by JavaScript. The fix is to identify the LCP element (usually a hero image), preload it with <link rel="preload" as="image">, serve it in WebP/AVIF format, and ensure it is not lazy-loaded.
CLS is caused by elements that move after initial render. The most common causes are: images without explicit width and height attributes (browser cannot reserve space), ads or embeds loading without reserved space, and web fonts causing FOUT (Flash of Unstyled Text). Fix images by always adding width and height attributes in HTML. For fonts, add font-display:swap and preload critical fonts. For ads, wrap them in a container with a fixed min-height.
Performance Score measures how fast your page actually loads for users — it is a weighted average of LCP, FCP, CLS, TBT, Speed Index, and TTI. Structure Score measures how well your page follows performance best practices — caching, compression, image formats, unused code removal. You can have a high Structure Score but slow Performance if your server is slow. You can have a high Performance Score but low Structure Score if your page is small but badly configured. Aim to improve both.
