Free Website Speed Test

A website speed test measures how fast a page loads and how smooth it feels to a real visitor, then scores it and lists what's slowing it down. This one runs Google's Lighthouse on both mobile and desktop and reports Performance, Accessibility, Best-Practices and SEO scores plus Core Web Vitals — free, no signup.

Paste your page URL above and hit Test speed. We run the official PageSpeed Insights / Lighthouse engine on both a simulated mobile device and desktop, then show your scores, Core Web Vitals, a page render, and a prioritized list of fixes ranked by how much time each one saves.

Yes — always both. Google evaluates them separately and uses mobile for ranking (it's mobile-first), so we run both in parallel and show them side by side. A page can look fine on a fast desktop and struggle on a mid-tier phone.

Lighthouse scores are 0–100: 90+ is good (green), 50–89 needs work (amber), under 50 is poor (red). Performance is the hardest to max out because it depends on your images, scripts and hosting. Aim for 90+ on mobile and passing Core Web Vitals — that's what actually helps users and rankings.

They're Google's real-user experience metrics. LCP (Largest Contentful Paint) is how fast the main content appears; INP (Interaction to Next Paint) is how quickly the page responds to taps and clicks; CLS (Cumulative Layout Shift) is how much the layout unexpectedly jumps around.

'Good' thresholds: LCP under 2.5 seconds, INP under 200 milliseconds, CLS under 0.1. A page passes the Core Web Vitals assessment only when all three are in the good range for most real visitors (75th percentile).

This tool shows them two ways: lab data (a fresh Lighthouse run, available for any URL) and field data from the Chrome UX Report (real Chrome users over the last 28 days). Field data is the real-world truth but only appears once a page has enough traffic; until then, use the lab numbers.

Lab data is a single controlled test in a simulated environment — perfect for debugging and reproducing issues. Field data is aggregated from real Chrome users visiting your site, so it reflects actual devices and networks. Google ranks on field data where it exists; use lab data to find and fix the cause.

Mobile is throttled to simulate a mid-tier phone on a slower connection, while desktop assumes a fast wired connection and more CPU. Heavy JavaScript and large images hurt mobile far more, so mobile scores are usually lower — and they matter more for ranking.

The lab test simulates load each time, so small run-to-run variation is normal — ads, third-party scripts and network conditions all move the number. Focus on the trend and the specific opportunities, not one exact score. Field data is steadier because it's averaged over many real users.

Work top-down through the opportunities this tool lists — they're sorted by time saved. The usual big wins: compress and correctly size images (and use modern formats like WebP/AVIF), remove unused JavaScript and CSS, defer non-critical scripts, enable caching and a CDN, and cut down third-party tags. Re-test after each change.

Most WordPress speed comes from three things: a caching plugin (page + object cache), an image-optimization plugin serving WebP, and trimming plugins/third-party scripts. Good hosting and a CDN help a lot too. Run this test before and after so you can see each change pay off in the score and Core Web Vitals.

Yes. Core Web Vitals are a confirmed Google ranking signal, and speed also affects rankings indirectly: a slow page loses visitors before they engage, which hurts the behavioural signals search engines watch. It won't outrank great content on its own, but among similar pages, the faster one wins.

It's a real but secondary factor — relevance, content quality and links matter more for where you rank. Think of speed as a tie-breaker and a conversion multiplier: it rarely makes a weak page rank #1, but a slow page leaks traffic and revenue at every step. Fix the big issues, then invest in content and citations.

Strongly. Study after study shows conversions drop and bounce rate climbs with every extra second of load time, especially on mobile. Speed is one of the cheapest conversion-rate improvements you can make — you're not buying more traffic, you're keeping the visitors you already have.

Google's PageSpeed Insights / Lighthouse is the industry standard and the data most other tools (including this one) are built on. This tool runs that same engine, adds both mobile and desktop in one place, surfaces real-user Core Web Vitals, and turns the audit into a plain-English, prioritized fix list — free and with no signup.

It uses the same official PageSpeed Insights / Lighthouse engine and the same underlying data, presented in one view with both strategies, real-user field data, and a clearer prioritized fix list. Free, no signup.

TTFB (Time to First Byte) is how long the server takes to send the first byte of the page — mostly your hosting, backend and CDN. A high TTFB delays everything after it, including LCP, so slow servers cap how fast a page can ever feel. Better hosting, caching and a CDN are the usual fixes.

You pass when LCP, INP and CLS are all in the 'good' range for the 75th percentile of your real visitors (field data). Practically: speed up your largest element for LCP, cut heavy/long JavaScript for INP, and reserve space for images, ads and fonts so nothing shifts for CLS. Fix, wait ~28 days for field data to update, re-check.

Indirectly, yes. A fast, well-built, crawlable page is easier for AI crawlers (GPTBot, PerplexityBot and others) to read — and they can't cite what they can't read. But speed alone won't get you recommended: AI names the brands its trusted sources talk about. Fix speed, make sure you're crawlable, then check whether AI actually recommends you — that's where Citenzo's AI visibility tools come in.