Technical SEOCWVSchema

The 2025 Technical SEO Checklist (for Non-Devs & Devs)

Two-lane checklist: quick wins anyone can do, plus developer-level fixes for Core Web Vitals, crawlability, and structured data.

SEA-IO Editorial Team avatarSEA-IO Editorial Team• SEO & Performance• 11/10/2025• 11 min read
Blueprint style technical SEO illustration

Most sites don’t need a rebuild—they need a clear checklist and a bias to ship. Use this two-lane approach to improve Core Web Vitals, fix indexation, and add structured data without boiling the ocean.

Lane 1: Quick wins (no dev required)

  • Set concise, benefit-driven titles (≈30–60 chars). Avoid duplicates.
  • Write meta descriptions (120–155 chars) that set expectations & include a CTA.
  • Ensure one <h1> per page. H2/H3 reflect the outline users actually read.
  • Compress/lazy-load images; prefer .webp. Add descriptive alt text.
  • Link informational pages to comparison/pricing pages. Avoid orphan pages.
  • Fix obvious 404s and redirect chains. Keep internal links up to date after renames.
Good enough beats perfect
A 70% fix rolled out to 100 pages is more valuable than a 100% fix on 5 pages. Iterate weekly.

Lane 2: Dev-level fixes

  • Reduce JS on first load. Defer non-critical scripts; split routes; consider partial hydration.
  • Ship critical CSS inline and async-load the rest. Remove unused CSS.
  • Cache HTML for short periods; cache static assets with long max-age + immutable.
  • Use HTTP/2 (or HTTP/3) and compression (br/gzip/zstd). Implement HSTS and a sane CSP.
  • Preload the LCP resource (image/font) and avoid layout thrash. Stabilize heights.

Crawlability & indexation

  • Make sure canonical URLs are absolute and consistent with internal links.
  • Expose /sitemap.xml and submit in Search Console.
  • Avoid parameter explosions. For faceted nav, canonicalize or add noindex where appropriate.
  • Return the right status codes. Don’t 200 a 404 page; don’t soft-404 useful content.

Structured data that matters

  • Organization (logo, URL, sameAs) to support knowledge panels.
  • WebSite with SearchAction for sitelinks search box.
  • BreadcrumbList on templates to clarify hierarchy.
  • For products: Product + Offer + AggregateRating (if applicable).

Monitoring & regression guards

  • Set CWV budgets and track LCP/CLS/INP by template weekly.
  • Automate link checking and sitemap diffs in CI.
  • Log CLS shifts and script size by route after each deploy.

Want a fast second opinion? Run the SEA-IO Technical SEO audit to combine PageSpeed data with AI-assisted recommendations and schema checks.