How fast is your website?

Common questions

What is a good Lighthouse performance score?

Google considers 90–100 a good score, 50–89 needs improvement, and below 50 is poor. A score above 90 means your pages load quickly and efficiently for most visitors. The score is a composite of four Core Web Vitals metrics: Largest Contentful Paint (LCP), Total Blocking Time (TBT), Cumulative Layout Shift (CLS), and First Contentful Paint (FCP).

Why is my mobile score lower than my desktop score?

Lighthouse simulates a mid-range Android phone on a 4G connection for mobile tests, while desktop tests assume fast hardware and broadband. Most real-world visitors — especially first-time ones — are on mobile, so the mobile score is the one that matters most for SEO and conversions. A gap of 20–30 points between mobile and desktop is common; a gap above 40 usually signals unoptimized images or render-blocking scripts.

How do I fix a slow website?

The three highest-impact fixes are: (1) compress and convert images to WebP or AVIF, (2) eliminate or defer render-blocking JavaScript and CSS, and (3) serve your site from a CDN close to your visitors. After that, enabling browser caching, reducing server response time (TTFB), and removing unused third-party scripts each add meaningful gains. Your Lighthouse report flags exactly which issues apply to your site and ranks them by potential impact.Read the full fix guide →