Question 1

What Next.js features support SEO?

Accepted Answer

SSR/SSG HTML, Metadata API, sitemaps, robots.txt, semantic structure, and performance (CWV). Crawlable content beats pure CSR. Use stable URLs, canonical tags, and structured data where appropriate.

Question 2

How do you add a sitemap in App Router?

Accepted Answer

Use app/sitemap.ts (or xml) to generate Sitemap standards output. Include only canonical URLs. Update as content changes. For huge sites, multiple sitemaps/index files.

Question 3

How do you handle canonical URLs with trailing slash and UTM params?

Accepted Answer

Define trailingSlash config consistently and set canonical to clean URLs without tracking params. Duplicate content from params hurts SEO. Middleware redirects can normalize hosts and slashes.

Question 4

Is client-only rendering bad for SEO?

Accepted Answer

Often yes for primary content — crawlers may get empty shells or delayed content. Critical content should be in server-rendered HTML. Client enhancements are fine for widgets.

Question 5

How do you implement JSON-LD in Next.js?

Accepted Answer

Render a <script type="application/ld+json"> in a Server Component with safe JSON serialization. Keep structured data accurate. Validate with rich results tools. Don't inject user content unsafely.

Question 6

Lead: SEO regression after migrating to App Router — approach?

Accepted Answer

Compare HTML snapshots, metadata merge bugs, indexing of soft-navigated content, CWV, and canonical rules; fix with golden URL tests in CI. Monitor Search Console. Ensure loading states aren't indexed as primary content. Revisit streaming + bot behavior assumptions.

SEO Next.js Interview Questions

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