Lighthouse.
Google's open-source tool that grades a webpage on speed, accessibility, SEO, and best practices.
Lighthouse is the audit tool built into Chrome DevTools (and at pagespeed.web.dev). It runs your site against a checklist and returns four 0 to 100 scores: Performance, Accessibility, Best Practices, and SEO.
Score targets for a healthy small-business site: 80+ on mobile Performance, 95+ on Accessibility and Best Practices, 100 on SEO. The SEO score is the easiest to ace. It's mostly checking that you have title tags, meta descriptions, valid schema, and a robots.txt.
Lighthouse uses a simulated slow connection, so the numbers are usually worse than what real visitors experience. Don't obsess over the exact score. Fix the items it flags.
Related terms
- Core Web Vitals (CWV)Google's three-number summary of how fast and stable your website feels.
- Largest Contentful Paint (LCP)How long it takes for the main content of your page to appear. Google cares a lot about this number.
- Cumulative Layout Shift (CLS)A score for how much content jumps around as your page loads. Lower is better.
Want to know where your site stands?
Fifteen minutes. I’ll find the lighthouse fix that’s costing you.