The scoring model
Website Scorer evaluates one submitted public page and a small set of essential resources. Individual checks receive a pass, warning or fail result. A pass contributes full points, a warning contributes partial points and a fail contributes no points for that check. Category scores are normalized to 100 before the overall weighting is applied.
Overall score: Performance 20% + SEO 20% + Mobile Experience 15% + Accessibility 15% + Security & Trust 15% + Content Quality 10% + Conversion Readiness 5%.
| Category | What it considers | Weight |
|---|
| Performance | Google Lighthouse lab data and Chrome UX Report real-user data when available, response time, transfer size and compression. | 20% |
| SEO | Title, meta description, canonical URL, headings, robots, sitemap, structured data and crawl foundations. | 20% |
| Mobile Experience | Viewport configuration, responsive media foundations and selected PageSpeed mobile signals. | 15% |
| Accessibility | Document language, image alternatives, form labels, landmarks and Lighthouse accessibility data when available. | 15% |
| Security & Trust | HTTPS, HTTP-to-HTTPS behavior and selected protective response headers. | 15% |
| Content Quality | Clear page topic, heading structure, readable content depth and basic metadata quality. | 10% |
| Conversion Readiness | Calls to action, contact routes, forms and privacy information. | 5% |
Data sources
Direct public-page inspection
The service retrieves the submitted page using a limited server-side HTTP request. It reads the final status, response headers and up to a bounded amount of public HTML. It does not log in, submit forms, execute attacks or crawl private network addresses.
AMP detection
The AMP result is a direct YES or NO signal. YES means that the retrieved HTML declares the AMP document attribute and loads the AMP runtime. It is a detection result, not a certificate that every AMP validation rule passes, and it does not add or remove points from the Website Score.
Google PageSpeed Insights
When the external service is available, Website Scorer requests separate mobile and desktop Lighthouse assessments for performance, accessibility, best practices and SEO. Mobile data remains the primary PageSpeed input to the combined Website Score when it is available, while both device profiles appear in the report. If PageSpeed is unavailable or rate-limited, the report remains available and uses the local fallback checks instead.
Lighthouse Scoring Calculator
Each available Mobile and Desktop lab report links to Google's official Lighthouse Scoring Calculator with the measured FCP, LCP, TBT, CLS, Speed Index, TTI when available, device profile and Lighthouse version prefilled. The calculator explores how those inputs affect the Performance score; it does not run a new website measurement.
Chrome UX Report
Recent real-user metrics are requested separately from the dedicated Chrome UX Report API at origin level for phone and desktop visitors. CrUX represents an aggregated rolling 28-day dataset and is available only when Google has enough eligible measurements. A missing CrUX record is not an audit failure and does not prevent the Lighthouse or local checks from being shown.
Essential site resources
The audit may request the origin's robots.txt and sitemap.xml and may check the HTTP version of the domain to assess redirection to HTTPS. The service does not crawl an entire website.
Score bands
- 90-100 - Excellent: strong automated foundations with relatively small remaining improvements.
- 75-89 - Strong: a solid website with identifiable opportunities.
- 60-74 - Needs work: several material issues should be prioritised.
- 40-59 - Weak: important technical or user-experience foundations are missing.
- 0-39 - Critical: major problems limit confidence in the page.
Scores are decision aids, not certifications. A high automated score does not prove legal compliance, security, search rankings, accessibility conformance or commercial performance.
Known limitations
- The audit focuses on one public page, not every route or user journey.
- JavaScript-rendered content may not appear in the server-retrieved HTML.
- Geography, hosting load and third-party availability can affect timing data.
- Automated accessibility checks cannot replace testing by people, assistive technologies and experts.
- Security checks cover visible transport and headers only; no vulnerability exploitation is attempted.
- Content and conversion checks indicate the presence of common elements, not their strategic quality.
Use the report responsibly. Only analyze public websites and do not treat the output as permission to test systems beyond the automated requests made by this service.