01
From checks to a grade
Each check passes fully, partly or not at all. A score is the weighted result of its checks, out of 100. The overall number is the average of the scores the scan could measure, so a measurement that failed never counts against a site.
02
The grades
- A In very good shape. A few small details remain.90+
- B Solid, with a few fixes that would make a clear difference.75+
- C It works, but several things are holding it back.60+
- D Important problems are costing this site visitors.40+
- E This site needs serious work before anything else.< 40
03
The eight scores
Search
- What it measures
- How easily Google and Bing can find and understand your pages.
- Why it matters
- If search engines can't read a page, people looking for you won't find it.
- How we measure it
- Lighthouse SEO checks, titles, headings, sitemap and structured data.
Accessibility
- What it measures
- How well people with a disability can use the site, including with a screen reader or a keyboard.
- Why it matters
- About one person in six lives with a disability, and many places require access by law.
- How we measure it
- Automated Lighthouse checks. They find part of the problems, not all of them.
Speed
- What it measures
- How quickly the page appears and reacts on a phone.
- Why it matters
- Slow pages lose visitors, and speed is one of the signals Google uses.
- How we measure it
- A Lighthouse test on a simulated slow phone.
Carbon
- What it measures
- An estimate of the energy used each time someone visits.
- Why it matters
- Lighter pages load faster, cost less to serve and pollute less.
- How we measure it
- Page weight with the Sustainable Web Design model, plus a green hosting check.
Languages
- What it measures
- Whether visitors can read the site in their language, and whether search engines know each version.
- Why it matters
- A visitor who lands on the wrong language often leaves.
- How we measure it
- The declared language, links between versions and hreflang tags.
AI readiness
- What it measures
- How well assistants like ChatGPT or Claude can read and quote your site.
- Why it matters
- More and more people ask an assistant before they search.
- How we measure it
- llms.txt, crawler rules, structured data and facts written as plain text.
Security
- What it measures
- How well the site protects visitors, and your name in email.
- Why it matters
- A weak setup can let someone frame your pages or send email as you.
- How we measure it
- HTTPS, security headers, cookies and domain records.
Privacy
- What it measures
- What starts tracking visitors before they have chosen anything.
- Why it matters
- Visitors expect a choice, and privacy laws often require one.
- How we measure it
- Outside services seen when the page loads. This is a signal, not a legal finding.
04
What a scan can't see
It can’t see consent settings, so a tracker on load is something to review, not proof of a violation.
Automated tools find only part of real accessibility problems. A good score doesn’t replace testing with people.
Speed is measured in a simulated test, so it can move between two scans of the same site, sometimes by 20 points or more.