SEO Checker
You audit web pages for SEO issues using a real browser — rendered meta tags, actual heading structure, real schema markup, mobile viewport behavior. This skill is read-only: observe and report, don't modify.
Tool Selection Rule
- Prefer existing tools first (code search, local files,
curl). Review HTML source, meta tags, and sitemap before opening the browser.
- Use Hanzi for Phase 2–5 — always open the browser for these phases even if Phase 1 found all static data. Do not substitute curl or WebFetch for browser phases.
Before Starting
Call browser_status to verify the extension is reachable. If unavailable, tell the user to install from: https://chromewebstore.google.com/detail/hanzi-browse/iklpkemlmbhemkiojndpbhoakgikpmcd
What You Need
- URL — page or site to audit
- Scope — single page, specific section, or full site (default: single page)
- Focus — any specific SEO concerns (e.g., "we're not showing up in rich results", "mobile traffic dropped")
Audit Phases
Phase 1 — Source Review (before browser)
Check what you can without a browser:
- Robots.txt: Fetch
<domain>/robots.txt — check for accidental Disallow: / or blocked important paths. Note: some sites serve different robots.txt to different user agents (UA sniffing). If the curl result looks suspicious or overly restrictive, verify with browser_start to see what a real browser receives.
- Sitemap: Fetch
<domain>/sitemap.xml — verify it exists and includes the target URL
- HTML source: If accessible, review raw
<head> for meta tags, canonical, hreflang
- Codebase (if source available): Scan for hardcoded noindex, missing meta tag templates, SEO component patterns
Summarize findings before opening the browser.
Phase 2 — Meta & Head Tags (browser)
Use browser_start to open the page and inspect the rendered DOM. JavaScript-rendered SPAs may have different meta tags than the raw HTML source.
- Title tag: Exists, 50-60 characters, unique, descriptive (not "Home" or "Untitled")
- Meta description: Exists, 150-160 characters, includes target keywords, compelling for CTR
- Canonical URL: Present, points to the correct URL (not a duplicate or wrong domain)
- Robots meta: Check for unintentional
noindex, nofollow, or none directives
- Open Graph tags:
og:title, og:description, og:image, og:url — all present and correct
- Twitter Card tags:
twitter:card, twitter:title, twitter:description, twitter:image
- Viewport meta:
<meta name="viewport" content="width=device-width, initial-scale=1"> present
- Charset & lang:
<meta charset="utf-8"> and <html lang="..."> set correctly
Screenshot the page after loading.
Phase 3 — Content Structure (browser)
- H1 tag: Exactly one per page, descriptive, contains primary keyword
- Heading hierarchy: H1 → H2 → H3 — no skipped levels (e.g., H1 → H3 with no H2)
- Image alt text: All meaningful images have descriptive alt text; decorative images use
alt=""
- Internal links: Key pages are linked, anchor text is descriptive (not "click here")
- Broken links: Check for obvious 404s or dead links on the page
Phase 4 — Structured Data (browser)
- JSON-LD / Microdata: Check
<script type="application/ld+json"> blocks in the rendered DOM
- Schema types: Verify appropriate types are used (Article, Product, LocalBusiness, BreadcrumbList, FAQ, etc.)
- Required properties: Each schema type has required fields — check they're populated (e.g., Article needs
headline, datePublished, author)
- Validation: Flag malformed JSON-LD or schemas with empty/placeholder values
Phase 5 — Mobile & Performance (browser)
Render the page at a mobile viewport (375×812, iPhone-sized):
- Mobile layout: No horizontal scrolling, text readable without zooming, tap targets at least 48×48px
- Content parity: Mobile version has the same key content as desktop (Google uses mobile-first indexing)
- Image optimization: Check for oversized images (e.g., 2000px wide image in a 375px container), missing
loading="lazy" on below-fold images
- CLS indicators: Elements that visibly shift during load (ads, images without dimensions, dynamically injected content)
- Core Web Vitals: Use
javascript_tool to extract real navigation timing from the Performance API:
const nav = performance.getEntriesByType('navigation')[0];
const paint = performance.getEntriesByType('paint');
({
ttfb: nav.responseStart - nav.requestStart,
domContentLoaded: nav.domContentLoadedEventEnd - nav.startTime,
load: nav.loadEventEnd - nav.startTime,
fcp: paint.find(e => e.name === 'first-contentful-paint')?.startTime,
});
Screenshot at mobile viewport.
Scoring
Rate each category on a 0-10 scale:
| Category |
What's checked |
| Meta Tags |
Title, description, canonical, robots, OG, Twitter cards |
| Content Structure |
H1, heading hierarchy, image alt text, internal links |
| Structured Data |
JSON-LD presence, correct types, required properties |
| Mobile |
Responsive layout, content parity, tap targets |
| Performance Signals |
Image sizes, lazy loading, CLS indicators |
| Internationalisation |
hreflang alternates, lang attribute, multilingual implementation |
Overall score = average of the 6 category scores (out of 10).
- 9-10: Excellent — production-ready SEO
- 7-8: Good — minor improvements needed
- 5-6: Needs work — several issues affecting visibility
- 3-4: Poor — significant SEO problems
- 0-2: Critical — major issues blocking indexing or ranking
Report Format
# SEO Audit: [URL]
Overall Score: [X]/10
## Meta Tags — [X]/10
✓ [What passed — one line each]
✗ [What failed — element, issue, specific fix]
📸 Screenshot: [evidence]
## Content Structure — [X]/10
✓ / ✗ [same format]
## Structured Data — [X]/10
✓ / ✗ [same format]
## Mobile — [X]/10
✓ / ✗ [same format]
## Performance Signals — [X]/10
✓ / ✗ [same format]
## Internationalisation — [X]/10
✓ / ✗ [same format]
## Top 3 Priorities
1. [Most impactful fix — what to do and why]
2. [Second priority]
3. [Third priority]
For each failing item, include:
- What's wrong: specific element and current value
- Why it matters: impact on search visibility or user experience
- How to fix: concrete action (e.g., "Add
<meta name="description" content="..."> with 150-160 chars describing the page")
- Reference: link to relevant Google/web.dev guideline where helpful
Rules
- One page at a time — screenshot at each phase
- Be specific: "the hero image (1920×1080, 2.4MB)" not "some images are large"
- Cite standards: Google's SEO guidelines, web.dev, Schema.org specs
- Don't report unverified issues — if the rendered DOM differs from source, note both
- If
browser_start times out, call browser_screenshot to diagnose
- Read-only — never modify the page, submit forms, or click CTAs
- SPA handling: always check rendered DOM, not just HTML source — SPAs may inject meta tags via JavaScript
1---2name: seo-checker3description: Audit web pages for SEO issues in a real browser. Checks rendered meta tags, heading hierarchy, image alt text, structured data, canonical URLs, mobile rendering, and performance signals. Produces a scored report with specific findings and fixes. Read-only — inspects, doesn't modify. Requires the hanzi browser automation MCP server and Chrome extension.4---56# SEO Checker78You audit web pages for SEO issues using a real browser — rendered meta tags, actual heading structure, real schema markup, mobile viewport behavior. This skill is read-only: observe and report, don't modify.910## Tool Selection Rule1112- Prefer existing tools first (code search, local files, `curl`). Review HTML source, meta tags, and sitemap before opening the browser.13- Use Hanzi for Phase 2–5 — always open the browser for these phases even if Phase 1 found all static data. Do not substitute curl or WebFetch for browser phases.1415## Before Starting1617Call `browser_status` to verify the extension is reachable. If unavailable, tell the user to install from: https://chromewebstore.google.com/detail/hanzi-browse/iklpkemlmbhemkiojndpbhoakgikpmcd1819## What You Need20211. **URL** — page or site to audit222. **Scope** — single page, specific section, or full site (default: single page)233. **Focus** — any specific SEO concerns (e.g., "we're not showing up in rich results", "mobile traffic dropped")2425## Audit Phases2627### Phase 1 — Source Review (before browser)2829Check what you can without a browser:3031- **Robots.txt**: Fetch `<domain>/robots.txt` — check for accidental `Disallow: /` or blocked important paths. Note: some sites serve different robots.txt to different user agents (UA sniffing). If the curl result looks suspicious or overly restrictive, verify with `browser_start` to see what a real browser receives.32- **Sitemap**: Fetch `<domain>/sitemap.xml` — verify it exists and includes the target URL33- **HTML source**: If accessible, review raw `<head>` for meta tags, canonical, hreflang34- **Codebase** (if source available): Scan for hardcoded noindex, missing meta tag templates, SEO component patterns3536Summarize findings before opening the browser.3738### Phase 2 — Meta & Head Tags (browser)3940Use `browser_start` to open the page and inspect the rendered DOM. JavaScript-rendered SPAs may have different meta tags than the raw HTML source.4142- **Title tag**: Exists, 50-60 characters, unique, descriptive (not "Home" or "Untitled")43- **Meta description**: Exists, 150-160 characters, includes target keywords, compelling for CTR44- **Canonical URL**: Present, points to the correct URL (not a duplicate or wrong domain)45- **Robots meta**: Check for unintentional `noindex`, `nofollow`, or `none` directives46- **Open Graph tags**: `og:title`, `og:description`, `og:image`, `og:url` — all present and correct47- **Twitter Card tags**: `twitter:card`, `twitter:title`, `twitter:description`, `twitter:image`48- **Viewport meta**: `<meta name="viewport" content="width=device-width, initial-scale=1">` present49- **Charset & lang**: `<meta charset="utf-8">` and `<html lang="...">` set correctly5051Screenshot the page after loading.5253### Phase 3 — Content Structure (browser)5455- **H1 tag**: Exactly one per page, descriptive, contains primary keyword56- **Heading hierarchy**: H1 → H2 → H3 — no skipped levels (e.g., H1 → H3 with no H2)57- **Image alt text**: All meaningful images have descriptive alt text; decorative images use `alt=""`58- **Internal links**: Key pages are linked, anchor text is descriptive (not "click here")59- **Broken links**: Check for obvious 404s or dead links on the page6061### Phase 4 — Structured Data (browser)6263- **JSON-LD / Microdata**: Check `<script type="application/ld+json">` blocks in the rendered DOM64- **Schema types**: Verify appropriate types are used (Article, Product, LocalBusiness, BreadcrumbList, FAQ, etc.)65- **Required properties**: Each schema type has required fields — check they're populated (e.g., Article needs `headline`, `datePublished`, `author`)66- **Validation**: Flag malformed JSON-LD or schemas with empty/placeholder values6768### Phase 5 — Mobile & Performance (browser)6970Render the page at a mobile viewport (375×812, iPhone-sized):7172- **Mobile layout**: No horizontal scrolling, text readable without zooming, tap targets at least 48×48px73- **Content parity**: Mobile version has the same key content as desktop (Google uses mobile-first indexing)74- **Image optimization**: Check for oversized images (e.g., 2000px wide image in a 375px container), missing `loading="lazy"` on below-fold images75- **CLS indicators**: Elements that visibly shift during load (ads, images without dimensions, dynamically injected content)76- **Core Web Vitals**: Use `javascript_tool` to extract real navigation timing from the Performance API:7778```javascript79const nav = performance.getEntriesByType('navigation')[0];80const paint = performance.getEntriesByType('paint');81({82 ttfb: nav.responseStart - nav.requestStart,83 domContentLoaded: nav.domContentLoadedEventEnd - nav.startTime,84 load: nav.loadEventEnd - nav.startTime,85 fcp: paint.find(e => e.name === 'first-contentful-paint')?.startTime,86});87```8889Screenshot at mobile viewport.9091## Scoring9293Rate each category on a 0-10 scale:9495| Category | What's checked |96|----------|---------------|97| **Meta Tags** | Title, description, canonical, robots, OG, Twitter cards |98| **Content Structure** | H1, heading hierarchy, image alt text, internal links |99| **Structured Data** | JSON-LD presence, correct types, required properties |100| **Mobile** | Responsive layout, content parity, tap targets |101| **Performance Signals** | Image sizes, lazy loading, CLS indicators |102| **Internationalisation** | hreflang alternates, lang attribute, multilingual implementation |103104**Overall score** = average of the 6 category scores (out of 10).105106- **9-10**: Excellent — production-ready SEO107- **7-8**: Good — minor improvements needed108- **5-6**: Needs work — several issues affecting visibility109- **3-4**: Poor — significant SEO problems110- **0-2**: Critical — major issues blocking indexing or ranking111112## Report Format113114```115# SEO Audit: [URL]116Overall Score: [X]/10117118## Meta Tags — [X]/10119✓ [What passed — one line each]120✗ [What failed — element, issue, specific fix]121 📸 Screenshot: [evidence]122123## Content Structure — [X]/10124✓ / ✗ [same format]125126## Structured Data — [X]/10127✓ / ✗ [same format]128129## Mobile — [X]/10130✓ / ✗ [same format]131132## Performance Signals — [X]/10133✓ / ✗ [same format]134135## Internationalisation — [X]/10136✓ / ✗ [same format]137138## Top 3 Priorities1391. [Most impactful fix — what to do and why]1402. [Second priority]1413. [Third priority]142```143144For each failing item, include:145- **What's wrong**: specific element and current value146- **Why it matters**: impact on search visibility or user experience147- **How to fix**: concrete action (e.g., "Add `<meta name="description" content="...">` with 150-160 chars describing the page")148- **Reference**: link to relevant Google/web.dev guideline where helpful149150## Rules151152- One page at a time — screenshot at each phase153- Be specific: "the hero image (1920×1080, 2.4MB)" not "some images are large"154- Cite standards: Google's SEO guidelines, web.dev, Schema.org specs155- Don't report unverified issues — if the rendered DOM differs from source, note both156- If `browser_start` times out, call `browser_screenshot` to diagnose157- Read-only — never modify the page, submit forms, or click CTAs158- SPA handling: always check rendered DOM, not just HTML source — SPAs may inject meta tags via JavaScript
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