Technical reports
The Technical group of the VitalSentinel SEO Extension checks the HTTP headers, technologies and tracking, accessibility and AI readiness of the page that you have open.
The Technical group has four reports: HTTP headers, Tech and tracking, Accessibility and AI readiness.
Before you start
- Open the popup and click Technical in the sidebar.
- The Tech and tracking, Accessibility and AI readiness reports start their checks when you open them. They show no issue count in the sidebar.
HTTP headers
The HTTP headers report shows the response that the browser got for the page. The extension records it while the page loads.
At the top, a tile shows the status code. Next to it, four facts:
| Fact | What it shows |
|---|---|
| Security | How many of the six security headers the response sets |
| Transport | The HTTP version, and HTTPS or Plain HTTP |
| Caching | The Cache-Control value, or No Cache-Control |
| Compression | Brotli, gzip, Zstandard, or None |
Redirect chain
The Redirect chain section lists each server redirect, with its status code, and then the final address. The extension warns about a chain of more than one hop, temporary redirects (302 and 307) and redirect loops. It also shows a redirect from HTTP to HTTPS and a client-side redirect.
Security headers
The Security headers section checks Strict-Transport-Security, Content-Security-Policy, X-Frame-Options, X-Content-Type-Options, Referrer-Policy and Permissions-Policy. An HSTS max-age of less than 6 months is a warning. If Content-Security-Policy sets frame-ancestors, the extension accepts it instead of X-Frame-Options.
Caching and compression
This section warns about HTML without compression and Cache-Control: public on a response that sets cookies. It also tells you about a missing Cache-Control header and Vary: User-Agent.
Response headers
The Response headers section lists every header of the final response. The extension removes cookie values from the record. Click Copy headers to copy all of the headers.
If the page loaded before the extension started, the report says "No response recorded for this page". Click Reload page to record the response. If a service worker answered the page, the browser has no network response to record, and the report says "Served by a service worker".
Tech and tracking
The Tech and tracking report reads the headers, the HTML, the scripts and the cookies of the page.
- Tech stack: the technologies that the extension found, in groups. The groups are CMS, E-commerce, Frameworks, Libraries, Server and CDN, Tag managers, Analytics, Advertising, Consent and Fonts.
- Trackers: the known tracker requests since the page started to load, with the vendor, the purpose and the number of requests.
- Consent Mode v2: the default value and the update of
ad_storage,analytics_storage,ad_user_dataandad_personalization. If the page sends no Consent Mode commands, the section says so. - Cookies: each cookie of the page, with its domain, purpose, flags and expiry.
If the page has a consent banner but no stored choice, analytics and marketing trackers and cookies loaded before consent. A red banner then shows their number, and red marks these cookies in the table. The extension also warns about marketing tags without a consent banner and Google tags without Consent Mode. It also tells you about cookies without the Secure flag.
Accessibility
The Accessibility report runs an automated audit with axe-core on the page. The tiles count the issues by impact: Critical, Serious, Moderate and Minor.
Each issue in the Issues section shows its impact, a link to the rule description and the number of elements. Up to five elements show with their CSS selector. For a color contrast issue, the row also shows the colors and the contrast ratio. The Passed section lists the rules that the page passed.
Click Run again after you change the page. Automated checks find about a third of WCAG issues. Keyboard and screen reader tests are still necessary.
AI readiness
The AI readiness report checks how well AI agents can read the page. A ring shows how many checks passed, with a verdict, for example "AI agents can read most of this page".
| Check | What the extension checks |
|---|---|
| llms.txt | If the site has an /llms.txt file, with its size and number of links |
| AI crawler access | If robots.txt blocks AI crawlers. Click Crawlers to see the rules |
| Content without JavaScript | If the main content is in the raw HTML. Most AI crawlers do not run JavaScript |
| Structured data | The structured data types of the page |
| Semantic HTML | The semantic elements, and if the page has a <main> element |
| Author and dates | If the author and the modified date are in the markup |
| Markdown version | If a .md version of the address exists, or if the server sends text/markdown |
| Sitemap | If the page is in the sitemap. Shows only after another report, for example Indexability, read the sitemaps |
| noai / noimageai | If the page sets the noai or noimageai opt-out |
| Page size for agents | The number of words and the size of the HTML |
Some checks are optional tips. The summary line shows how many checks passed, how many to fix and how many are optional.
For AI readability on all the pages of a domain, see AI readability. For the AI bots that visit your site, see AI bots.
Related
- Crawl and index reports - robots.txt, sitemaps and raw HTML
- Privacy and permissions - why the extension reads cookies and headers
- Site Health Monitoring - technical checks for all the pages of a domain
Performance
The Performance report of the VitalSentinel SEO Extension shows Core Web Vitals measured on your device, CrUX data, an on-page overlay and a resource audit.
VitalSentinel tab
The VitalSentinel tab of the extension shows the last 90 days of your VitalSentinel data for the page, and adds the page to Page Monitoring with Watch this page.
