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What site checks cover
A site check loads one page in Chromium on a desktop screen (1366 × 800) and a phone screen (390 × 844), then checks its links, robots.txt, sitemap and certificate. Every finding comes from a measurement, never a guess.
How the score works
Each area starts at 100. Critical findings take off 30 points, warnings 12 and notices 4. Speed is scored from the measurements themselves. The overall score weights reliability 30%, speed 20%, SEO 20%, accessibility 15% and security 15%. A check counts as Issues found when it has at least one critical finding.
Reliability
| HTTP status | Critical if the page answers with 400 or above. |
| JavaScript errors | Uncaught errors and console errors while loading. Warning, or critical at five or more. |
| Failed requests | Scripts, styles, images or API calls that returned an error or didn't load. |
| Broken links | Up to 40 links on your site and 20 elsewhere, at most three at a time per server. 404, 410 and 5xx count as broken; pages that block bots or need a login are listed as “couldn't be verified” instead. |
| Redirects | A notice if the page redirects three or more times. |
Speed
| Largest Contentful Paint | Good up to 2.5 s, warning to 4 s, critical above. |
| Server response (TTFB) | Good up to 0.8 s, warning to 1.8 s, critical above. |
| Layout shift (CLS) | Good up to 0.1, warning to 0.25, critical above. |
| Page weight | Warning above 3 MB, critical above 6 MB, with a breakdown by file type. |
| Requests | A notice above 150 requests. |
Measurements come from a server with a fast connection, so real visitors on phones will usually see slower numbers.
SEO
| noindex | Critical if a robots meta tag or X-Robots-Tag header keeps the page out of search. |
| Title and description | Present, and a sensible length. |
| Headings | One H1. |
| Canonical URL | Set. |
| robots.txt and sitemap | Found, and robots.txt doesn't block every crawler. |
| Link previews | Open Graph title and image, used by Slack, LinkedIn and WhatsApp. |
Accessibility
| Alt text | Visible images without an alt attribute. |
| Labels | Form fields with no label or aria-label. A placeholder alone doesn't count. |
| Names | Buttons and links with no text or accessible name. |
| Language | The html element declares a language. |
| Mobile | A viewport tag, zoom allowed, and no sideways scrolling on a phone. |
These are the basics a machine can check reliably. They don't replace a review with a screen reader.
Security
| HTTPS and certificate | Valid certificate; warning at under 30 days to expiry, critical under 14. |
| http to https | The plain http address redirects to https. |
| Headers | HSTS, Content-Security-Policy, X-Content-Type-Options, and protection against framing. |
| Mixed content | Files loaded over http on an https page. |
AI crawler access
The report shows whether your robots.txt lets GPTBot (OpenAI), ClaudeBot (Anthropic), Google-Extended, PerplexityBot and CCBot (Common Crawl) in. It doesn't affect the score: whether to allow them is your call.
If the check is blocked
Some firewalls and bot protection answer automated browsers with a challenge page. The check then stops with Blocked instead of scoring a page it couldn't see. Allow requests whose user agent contains Clickwalker; see our crawler for details.
Stuck? Email hello@clickwalker.com with the flow you're writing and we'll help.