/seo-audit - SEO Technical Audit

Audit web application source code for SEO issues - meta tags, structured data, content structure, Core Web Vitals indicators, and crawlability - producing a scored report with actionable fixes.

Target: $ARGUMENTS

When to Use

Before launching a new website or landing page
After major frontend refactors that may have broken SEO
When organic search traffic has dropped
During framework migration (SSR/SSG changes)
When adding i18n and need hreflang setup
Before a marketing campaign that depends on organic traffic
NOT for: content strategy or keyword research (use @marketing SEO mode)
NOT for: design or UX issues (use /design-review)
NOT for: pure performance optimization (use @perf)

Workflow

Step 1: Scope & Rendering Strategy Detection

Identify pages/routes to audit:

# Find page/route files
find $TARGET -path "*/pages/*" -o -path "*/app/*" -o -path "*/routes/*" | grep -E "\.(tsx?|vue|svelte|astro)$" | grep -v "_\|layout\|error\|loading" | head -30

Detect rendering strategy:

# Check for SSR/SSG configuration
grep -rn "getStaticProps\|getServerSideProps\|generateStaticParams\|getStaticPaths" $TARGET --include="*.ts" --include="*.tsx" 2>/dev/null | head -10
grep -rn "defineNuxtConfig\|ssr:\|prerender" $TARGET --include="*.ts" --include="*.config.*" 2>/dev/null | head -5
grep -rn "export const prerender\|export const ssr" $TARGET --include="*.ts" --include="*.svelte" 2>/dev/null | head -5

Classify: SSR (server-rendered), SSG (static), CSR (client-only), ISR (incremental), Hybrid

Output:

## Scope
- Pages: [N] routes detected
- Framework: [Next.js/Nuxt/SvelteKit/Astro/other]
- Rendering: [SSR/SSG/CSR/ISR/Hybrid]
- i18n: [detected/not detected]

Step 2: Technical SEO Audit

Check meta tags and structured data for each page:

Check	What to Look For	Impact
Title tag	Unique, 50-60 chars, keyword-rich	HIGH
Meta description	Unique, 150-160 chars, compelling	HIGH
Open Graph tags	og:title, og:description, og:image, og:url	MEDIUM
Twitter cards	twitter:card, twitter:title, twitter:image	MEDIUM
Canonical URL	Self-referencing canonical on every page	HIGH
Robots meta	Proper noindex/nofollow where needed	HIGH
Structured data	JSON-LD for relevant schema types	MEDIUM
Hreflang	Present if multi-language	HIGH (if i18n)
Favicon	Present and proper size	LOW

# Check for meta tag implementation
grep -rn "title\|meta.*description\|og:title\|twitter:card" $TARGET --include="*.tsx" --include="*.vue" --include="*.svelte" --include="*.astro" 2>/dev/null | head -20

# Check for Head/Meta components (framework-specific)
grep -rn "Head>\|useHead\|useSeoMeta\|<svelte:head\|Astro.props" $TARGET --include="*.tsx" --include="*.vue" --include="*.svelte" --include="*.astro" 2>/dev/null | head -15

# Check for JSON-LD structured data
grep -rn "application/ld+json\|structuredData\|jsonLd" $TARGET --include="*.tsx" --include="*.vue" --include="*.svelte" 2>/dev/null | head -10

Step 3: Content Structure Audit

Check	Criteria	Severity
H1 tag	Exactly one H1 per page	HIGH
Heading hierarchy	Logical H1 → H2 → H3, no skipped levels	MEDIUM
Alt text	All images have descriptive alt text	HIGH
Internal links	Meaningful anchor text, no "click here"	MEDIUM
Content length	Adequate content for the page type	LOW
Semantic HTML	Proper use of `<article>`, `<nav>`, `<main>`, `<section>`	MEDIUM

# Check heading usage
grep -rn "<h1\|<h2\|<h3\|<H1\|<H2\|<H3" $TARGET --include="*.tsx" --include="*.vue" --include="*.svelte" 2>/dev/null | head -20

# Check for missing alt text
grep -rn "<img\|<Image" $TARGET --include="*.tsx" --include="*.vue" --include="*.svelte" 2>/dev/null | grep -v "alt=" | head -10

# Check semantic HTML usage
grep -rn "<article\|<section\|<nav\|<main\|<aside\|<header\|<footer" $TARGET --include="*.tsx" --include="*.vue" --include="*.svelte" 2>/dev/null | wc -l

Step 4: Performance & Core Web Vitals Indicators

Check code-level indicators that affect CWV:

Check	CWV Metric	What to Look For
Image optimization	LCP	next/image, lazy loading, srcset, WebP/AVIF
Font loading	CLS	display:swap, font preloading, system font fallback
JS bundle size	FID/INP	Dynamic imports, code splitting, tree shaking
CSS loading	CLS	Critical CSS inline, non-blocking stylesheet loading
Layout shifts	CLS	Explicit width/height on images, skeleton screens
Third-party scripts	FID/INP	Deferred/async loading, script placement

# Image optimization
grep -rn "<img\|<Image" $TARGET --include="*.tsx" --include="*.vue" 2>/dev/null | grep -v "loading=\|lazy\|next/image\|nuxt-img" | head -10

# Font loading strategy
grep -rn "font-display\|@font-face\|display.*swap" $TARGET --include="*.css" --include="*.tsx" 2>/dev/null | head -5

# Dynamic imports (code splitting)
grep -rn "dynamic(\|lazy(\|import(" $TARGET --include="*.tsx" --include="*.vue" --include="*.ts" 2>/dev/null | grep -v "node_modules" | head -10

# Third-party scripts
grep -rn "<script.*src=\|<Script" $TARGET --include="*.tsx" --include="*.vue" --include="*.html" 2>/dev/null | head -10

Step 5: Crawlability Audit

Check	What to Look For
robots.txt	Exists, allows critical paths, blocks /api and admin
Sitemap	sitemap.xml exists and includes all public routes
404 page	Custom 404 with navigation, proper status code
Redirects	No redirect chains (>2 hops), 301 for permanent
URL structure	Clean, descriptive slugs, no query params for content
SPA concerns	Prerendering for CSR apps, proper hydration
Dynamic routes	Meta tags set per-route, not hardcoded

# Check for robots.txt
find . -name "robots.txt" -not -path "*/node_modules/*" 2>/dev/null

# Check for sitemap
find . -name "sitemap*" -not -path "*/node_modules/*" 2>/dev/null
grep -rn "sitemap" $TARGET --include="*.ts" --include="*.config.*" 2>/dev/null | head -5

# Check for 404 page
find $TARGET -name "404*" -o -name "not-found*" -o -name "\[...slug\]*" 2>/dev/null | head -5

# Check for redirect configuration
grep -rn "redirect\|rewrite" $TARGET --include="*.config.*" --include="*.ts" 2>/dev/null | head -10

Step 6: Scoring & Report

Score each category 0-100:

Score Range	Rating
90-100	Excellent
70-89	Good
50-69	Needs Work
0-49	Critical

Scoring formula per category:

Start at 100
CRITICAL finding: -25 points
HIGH finding: -15 points
MEDIUM finding: -10 points
LOW finding: -5 points
Minimum: 0

Verification Protocol

Before claiming the audit is complete:

All 5 audit dimensions were checked (technical SEO, content, CWV, crawlability, rendering)
Every finding has severity level and file:line reference
Rendering strategy was correctly identified and audit was adapted to it
Framework-specific meta patterns were checked (not just raw HTML)
At least 3 pages/routes were individually scanned
Scores were calculated with the formula above

Anti-Rationalization

Excuse	Reality
"SEO doesn't matter for our app"	Even SaaS apps need landing pages that rank. SEO drives organic acquisition at zero marginal cost.
"We'll add meta tags later"	Missing meta tags from day 1 means lost indexing time. Search engines need weeks to crawl and rank.
"It's a SPA, SEO doesn't apply"	SPAs need SSR/SSG for SEO. If Google can't render it, it doesn't exist in search results.
"Our content is good enough"	Good content with bad technical SEO is invisible. Fix the plumbing so the content can flow.
"The framework handles SEO"	Frameworks provide tools, not configuration. You still need proper meta, structured data, and sitemap.
"We don't need structured data"	Rich snippets increase CTR by 20-40%. Structured data is free visibility in search results.
"We'll do SEO after launch"	Retrofitting SEO is 3-5x more expensive than building it in. Especially for routing and rendering changes.

Rules

Read-only - Never modify files during an audit
Framework-aware - Check framework-specific meta patterns, not just raw HTML
Rendering-aware - Adapt checks to SSR/SSG/CSR strategy
Score every category - Use the scoring formula consistently
Evidence required - Every finding needs a file:line reference
Prioritize by impact - CRITICAL findings first, always
No vanity metrics - Focus on technical SEO, not keyword density or word count

Output

──── /seo-audit ────
Target: $ARGUMENTS
Framework: [detected]
Rendering: [SSR/SSG/CSR/Hybrid]
Pages scanned: [N]

Technical SEO:  [score]/100 - [N findings]
Content:        [score]/100 - [N findings]
Performance:    [score]/100 - [N findings]
Crawlability:   [score]/100 - [N findings]

Severity:
  CRITICAL: N
  HIGH: N
  MEDIUM: N
  LOW: N

Top Findings:
1. [CRITICAL] [description] - [file:line]
2. [HIGH] [description] - [file:line]
3. [HIGH] [description] - [file:line]

Overall SEO Score: [N]/100
Rating: [Excellent | Good | Needs Work | Critical]

seo-audit