Next.js App Router SEO optimization and auditing. Use when implementing or fixing SEO in a Next.js app — metadata and generateMetadata, viewport/themeColor, Open Graph and og/twitter images (file conventions + ImageResponse), web app manifest, favicons/icons, sitemap.xml, robots.txt, canonical URLs,

Next.js SEO Start from the page's task, production response and observed search behavior. Read the installed Next.js version and relevant node modules/next/dist/docs/ pages (bundled from 16.2); otherwise use matching official documentation. Metadata , Viewport and MetadataRoute types are also in node modules/next/dist/lib/metadata/types/metadata interface.d.ts . Keep framework APIs, caching mode and deployment policy consistent with the project. Useful, distinct content matters more than a longer page. Give titles, headings and descriptions separate jobs; add a FAQ, summary, badges or extra pages only when they help the reader. Publication dates must reflect meaningful changes. Verify authorship, credentials and factual claims. Implementation and audit scope Verify public URLs, redirects, status codes, crawl rules, index directives and canonicals before adding markup. A sitemap supports discovery; it does not make a page indexable or guarantee indexing. Keep important public content available in the served HTML when practical. A Client Component can be server prerendered; use client alone does not remove content from HTML. Use the App Router Metadata API and file conventions. Resolve relative metadata URLs with the correct production metadataBase and verify emitted absolute URLs. Do not rely on missing base behavior across versions/hosts. Configure refresh/invalidation for data backed pages, metadata and sitemaps. A database query alone does not guarantee publication updates reach them. With Cache Components enabled, follow the installed Next.js caching docs ( node modules/next/dist/docs/ ); caching is a freshness decision rather than a required SEO directive. Structured data must describe real visible content and a supported consumer. Check current rich result eligibility instead of adding every schema type. Preserve the owner's crawler policy. Training, search and user triggered retrieval have different controls; robots rules are not access control. Read for the affected area [Metadata](references/metadata api.md): inheritance, social images, icons and streaming. [Sitemaps/robots](references/sitemap robots.md): discovery, localization and preview policy. [Structured data](references/json ld.md): current eligibility and safe serialization. [AI search](references/ai search.md): crawler purposes, policy and evidence. [Audit checklist](references/checklist.md): scoped production and Search Console checks. [Troubleshooting](references/troubleshooting.md): indexing, HTML and hydration diagnosis. Separate evidence in the report: a performance export shows queries/traffic; URL Inspection and indexing reports address crawl/index/canonical status; field measurements address Core Web Vitals. Lighthouse is a lab diagnostic and cannot establish field INP. Good field thresholds at the 75th percentile are LCP ≤ 2.5 s, INP ≤ 200 ms and CLS ≤ 0.1. Verify status, headers and complete production HTML, including relevant bot responses, then open the route directly and test its interaction. A spoofed User Agent tests response handling, not actual verified bot access. Report unavailable checks explicitly and avoid ranking, indexing or citation promises.

nextjs-seo