Google Lighthouse: what do those scores mean?

What is Google Lighthouse?

Google Lighthouse is a free tool from Google that rates your website on 4 areas. Each category gets a score from 0 to 100. The higher, the better.

You can test it yourself via PageSpeed Insights. Enter your URL and Google does the rest.

The 4 categories

Performance

This measures how fast your website loads. Google looks at:

• First Contentful Paint (FCP): when does the visitor see the first bit of content?
• Largest Contentful Paint (LCP): when has the largest element loaded?
• Cumulative Layout Shift (CLS): do elements shift while loading?
• Total Blocking Time (TBT): how long is the page "frozen"?

Score	Rating
90-100	Excellent
50-89	Needs improvement
0-49	Poor

Our websites score 95+ on Performance as standard.

Accessibility

Can everyone use your website, including people with disabilities?

• Do images have alt text?
• Is there enough colour contrast?
• Does the site work with a keyboard?
• Are forms properly labelled?

This is not only good for users, but also for SEO. Google values accessible websites.

Best Practices

Does your website follow the technical standards?

• Is HTTPS being used?
• Are there JavaScript errors in the console?
• Are images served in the right format?
• Is the site protected against known vulnerabilities?

SEO

The basic SEO check in Lighthouse looks at:

• Does every page have a title tag?
• Is there a meta description?
• Are heading tags (H1, H2) in a logical order?
• Is the site mobile-friendly?
• Can Google crawl the page?

Heads up: a Lighthouse SEO score of 100 doesn't automatically put you at the top of Google. It means the technical foundation is in order.

What's a good score?

For most websites:

• 90+ across all categories = excellent
• 70-89 = acceptable but could be better
• Under 70 = action needed

Common mistakes that lower your score

1. Unoptimised images: use WebP format and lazy loading
2. Too much JavaScript: every plugin or script slows your site down
3. No caching: the same files get loaded over and over
4. Render-blocking resources: CSS and JS that block loading
5. Missing meta tags: they cost you SEO points

Test your own website

Curious how your website scores? Take our free SEO check and you'll receive a complete report with improvement points.

Or test it yourself on PageSpeed Insights.

Our scores

At Friday Webs our websites consistently score:

• Performance: 95-100
• Accessibility: 95-100
• Best Practices: 95-100
• SEO: 100

That's no coincidence: it comes down to how we build. No WordPress, no heavy plugins, no compromises on speed.

Further reading

• Core Web Vitals: the metrics Google cares about: a deeper dive into the Performance metrics
• Why speed is everything for your website: why Performance matters for your business
• WordPress vs custom website: technical comparison: why WordPress often scores poorly