If you can't see meta tags in View Source, neither can Google. Most Nuxt SEO bugs come from hydration mismatches, configuration mistakes, or disabling SSR where you shouldn't.
Two different ways to view HTML show different content:
View Source (Right-click → View Page Source) shows the initial HTML your server sends. This is what Google's crawler sees first.
Inspect Element (F12 → Elements tab) shows the live DOM after JavaScript executes. Meta tags added by JavaScript appear here but might not be indexed.
Test: Open your site, right-click, select "View Page Source." Search for <title> or <meta name="description". If you can't find your content in View Source, Google can't either.
<!-- ❌ BAD: Empty in View Source (SPA mode) -->
<!DOCTYPE html>
<html>
<head>
<title>Loading...</title>
</head>
<body>
<div id="__nuxt"></div>
<script src="/_nuxt/entry.js"></script>
</body>
</html>
<!-- ✅ GOOD: Content in View Source (SSR mode, default) -->
<!DOCTYPE html>
<html>
<head>
<title>How to Debug Nuxt SEO | MySite</title>
<meta name="description" content="Fix meta tags not rendering in Nuxt apps...">
</head>
<body>
<div id="__nuxt">
<h1>How to Debug Nuxt SEO</h1>
<p>Fix meta tags not rendering...</p>
</div>
<script src="/_nuxt/entry.js"></script>
</body>
</html>
Google renders JavaScript but it's a two-wave process: crawl the HTML first, then render JavaScript days later. If critical content only appears after JavaScript executes, indexing gets delayed by weeks.
Single Page Applications change routes without full page reloads. Meta tags set during initial render might not update when users navigate.
Common mistake: Using document.title instead of Nuxt's composables.
<!-- ❌ Doesn't work on navigation -->
<script setup>
const route = useRoute()
watch(() => route.path, () => {
document.title = route.meta.title // Won't update in head manager
})
</script>
Fix: Use useHead() or useSeoMeta(). Nuxt tracks navigation and updates meta tags correctly.
<!-- ✅ Updates on every navigation -->
<script setup>
const route = useRoute()
useHead({
title: () => route.meta.title as string
})
</script>
Nuxt's Unhead integration synchronizes meta tags across SSR and client-side navigation. The Unhead documentation explains reactivity patterns.
Nuxt DevTools provides a dedicated view for monitoring meta tags:
If meta tags don't change, you're not using reactive values correctly or have SSR disabled.
Hydration is when Vue takes server-rendered HTML and "activates" it with reactivity and event listeners. A hydration mismatch occurs when the HTML rendered on the client differs from the server-rendered HTML.
Nuxt displays warnings like "Hydration completed but contains mismatches" or "Text content does not match server-rendered HTML." These warnings appear in browser console and indicate server/client HTML differences (Vue SSR Guide).
Invalid HTML nesting triggers browser auto-correction, causing mismatches:
<!-- ❌ Invalid: div inside p -->
<template>
<p /><div>Content</div> <!-- Browser auto-closes <p> before <div> -->
</template>
<!-- ✅ Valid HTML structure -->
<template>
<div>
<p>Content</p>
</div>
</template>
Browser-only APIs don't exist during SSR:
<!-- ❌ Crashes during SSR -->
<script setup>
const userAgent = window.navigator.userAgent
</script>
<!-- ✅ Only access on client -->
<script setup>
const userAgent = ref('')
onMounted(() => {
userAgent.value = window.navigator.userAgent
})
</script>
Random values and timestamps differ between server and client:
<!-- ❌ Different on server vs client -->
<script setup>
const randomId = Math.random()
const timestamp = new Date().toLocaleString()
</script>
<!-- ✅ Use ClientOnly or onMounted -->
<script setup>
const randomId = ref('')
const mounted = ref(false)
onMounted(() => {
mounted.value = true
randomId.value = Math.random().toString()
})
</script>
<template>
<div v-if="mounted">
ID: {{ randomId }}
</div>
</template>
Third-party libraries without SSR support cause mismatches (How to Fix Vue Hydration Mismatch):
<!-- Wrap client-only libraries -->
<template>
<ClientOnly>
<GoogleMap />
</ClientOnly>
</template>
For inevitable mismatches (like timestamps), use data-allow-mismatch:
<template>
<time :data-allow-mismatch="true">
{{ new Date().toLocaleString() }}
</time>
</template>
This tells Vue to expect differences and skip warnings.
HTML minification causes hydration mismatches. Most HTML minifiers must be disabled (Harlan Wilton - Nuxt 3 Hydration Mismatch).
Cloudflare users: Disable Cloudflare's automatic HTML minifier in dashboard → Speed → Optimization → Auto Minify.
Browser cache loads outdated JavaScript. Clear cache when debugging mismatches.
Most Nuxt SEO bugs come from configuration errors or disabling features that shouldn't be disabled.
Setting ssr: false in nuxt.config.ts breaks SEO for the entire site:
// ❌ Disables SSR globally (bad for SEO)
export default defineNuxtConfig({
ssr: false
})
Fix: Remove global SSR disable or use route-level rules:
// ✅ Disable SSR only where needed
export default defineNuxtConfig({
routeRules: {
'/dashboard/**': { ssr: false }, // Client-only for authenticated routes
'/blog/**': { prerender: true } // SSG for blog pages
}
})
Passing .value instead of the ref breaks reactivity:
<script setup>
const pageTitle = ref('Loading...')
// ❌ Loses reactivity
useHead({
title: pageTitle.value
})
// ✅ Stays reactive
useHead({
title: pageTitle
})
// Later update works with reactive version
pageTitle.value = 'Loaded Content'
</script>
For computed values, use getter functions:
<script setup>
const post = ref({ title: 'Loading...' })
useHead({
title: () => post.value.title // Updates when post changes
})
</script>
Multiple useHead() calls with same meta tags create duplicates:
<!-- ❌ Creates 2 description tags -->
<script setup>
useHead({
meta: [{ name: 'description', content: 'First description' }]
})
useHead({
meta: [{ name: 'description', content: 'Second description' }]
})
</script>
Unhead deduplicates by default but multiple calls can override unexpectedly. Consolidate meta tags into single useHead() or useSeoMeta() call per component.
Data fetched in onMounted() won't be available during SSR:
<!-- ❌ Client-only fetch -->
<script setup>
const post = ref({ title: 'Loading...' })
onMounted(async () => {
post.value = await fetch('/api/post').then(r => r.json())
})
useHead({ title: () => post.value.title })
</script>
<!-- ✅ SSR-compatible fetch -->
<script setup>
const { data: post } = await useFetch('/api/post')
useHead({ title: () => post.value?.title || 'Loading...' })
</script>
Nuxt's useFetch() and useAsyncData() work during both SSR and client-side navigation.
DevTools helps debug meta tags, rendering issues, and JavaScript errors.
Network panel shows server-sent HTML before JavaScript executes:
Look for meta tags in this response. If missing, your SSR isn't working.
Elements panel lets you find all meta tags quickly:
<meta name="description"Compare what you find against your useHead() calls.
JavaScript errors break meta tag updates. Console shows Vue warnings and Unhead errors.
Look for:
Fix errors before debugging meta tags. Broken JavaScript breaks everything.
Lighthouse tab includes basic SEO checks:
Checks:
<title> element<html> has lang attributeLighthouse doesn't verify correctness—just presence. A title "undefined" passes but isn't useful.
URL Inspection tool shows exactly what Google sees when crawling your page.
Tool shows (Google URL Inspection documentation):
"URL is on Google" means the URL is eligible to appear in search results (not guaranteed). "URL is not on Google" means the URL can't appear—check "Page indexing" section for why.
See how Google renders your page:
Compare screenshot to your actual page. Missing content indicates rendering problems.
Google renders JavaScript but processes happen in two waves:
If content only appears after JavaScript, it gets delayed. URL Inspection shows both:
After fixing issues:
Google doesn't guarantee indexing—it still evaluates content quality.
Daily quota limits requests. For bulk operations, use Google Indexing API (up to 2,000 URLs/day).
Cause: SSR disabled globally or for specific routes.
Test:
curl -s https://yoursite.com | grep "<title>"
If curl shows empty title, check nuxt.config.ts for ssr: false or route rules disabling SSR.
Fix: Re-enable SSR:
// nuxt.config.ts
export default defineNuxtConfig({
// Remove ssr: false if present
// Or use route-level control
routeRules: {
'/dashboard/**': { ssr: false }, // Only disable for client-only sections
}
})
Cause: Not using reactive values or using document.title directly.
Test: Navigate between pages, watch <title> in Nuxt DevTools Head tab.
Fix:
<script setup>
const route = useRoute()
useHead({
title: () => route.meta.title as string
})
</script>
Cause: Google rewrites 60-70% of meta descriptions and titles it deems low-quality.
Test: Search for site:yoursite.com in Google. Compare displayed titles to your actual meta tags.
Fix: Write better titles and descriptions:
Google still might rewrite—that's normal. If it rewrites everything, your meta tags are probably too generic or off-topic.
Cause: Server and client render different meta tag values (timestamps, random IDs, browser APIs).
Test: Look for console warnings: "Hydration completed but contains mismatches."
Fix: Use ClientOnly wrapper or data-allow-mismatch:
<script setup>
const timestamp = ref('')
onMounted(() => {
timestamp.value = new Date().toISOString()
})
useHead({
meta: [
{ property: 'og:updated_time', content: timestamp }
]
})
</script>
Cause: Data fetched in onMounted() instead of during SSR.
Test: View Source shows "Loading..." instead of actual content.
Fix: Use useFetch() or useAsyncData():
<!-- ❌ Client-only fetch -->
<script setup>
const post = ref({ title: 'Loading...' })
onMounted(async () => {
post.value = await fetch('/api/post').then(r => r.json())
})
useHead({ title: () => post.value.title })
</script>
<!-- ✅ SSR-compatible fetch -->
<script setup>
const { data: post } = await useFetch('/api/post')
useHead({ title: () => post.value?.title || 'Loading...' })
</script>
Don't wait for Google to tell you something's broken. Test locally:
Right-click → View Page Source. Search for critical meta tags. If they're missing, fix SSR before deploying.
# Check initial HTML
curl -s https://yoursite.com | grep -A 5 "<head>"
# Check specific meta tag
curl -s https://yoursite.com | grep 'name="description"'
Should show full meta tags in output.
Set up staging site in Search Console. Test URL Inspection on staging before pushing to production.
Automate SEO checks in CI/CD:
npm install -g @lhci/cli
# Run Lighthouse
lhci autorun --collect.url=http://localhost:3000
Configure assertion for minimum SEO score.
Enable DevTools in production for debugging (temporarily):
// nuxt.config.ts
export default defineNuxtConfig({
devtools: {
enabled: true // Normally auto-disabled in production
}
})
Remember to disable after debugging—DevTools add overhead.