SEO Basics (Developer's Lens)

SEO is the overlap of: a crawler can see your page, it understands what the page is about, and users actually want to visit it. Optimize in that order.

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Technical SEO (you control this)

  • Every important page has a stable, canonical URL (no trailing-slash / case mismatches).
  • Serve 200 on canonical, 301 on old URLs — never 404 or 302 for permanent moves.
  • robots.txt allows crawl of public pages; blocks admin / auth.
  • Submit a sitemap.xml (even a small one) in Google Search Console.
  • Render server-side or use SSG for content pages — JS-heavy SPAs crawl worse than static HTML.

On-page signals

  • One <h1> per page, matching the primary topic/keyword.
  • Meta title 50-60 chars, description 140-160 — these are your search-result snippet.
  • Use descriptive, keyword-rich URLs (`/tools/json-formatter`, not `/t/42`).
  • Alt text on images with a real subject (not `image1.png`).
  • Internal linking — link from strong pages to the pages you want to rank.

Structured data

  • Add JSON-LD for Organization, WebSite, SoftwareApplication, FAQ — gets you rich results.
  • Use schema.org types, validate at validator.schema.org before deploy.

Don't bother with

  • `keywords` meta tag — ignored by Google since ~2009.
  • Exact-match keyword stuffing — penalized.
  • Tiny frequent tweaks — SEO changes take weeks to show. Be patient.

Further reading