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Technical SEO basics2 min read

The complete technical checklist

20 actionable points to verify markup, URLs, HTTP statuses, and structured data before moving on to content production.

Before shifting focus to content production, this checklist rounds up the technical fundamentals covered in the previous modules into 20 points. Use it as a verification grid before any major publication or redesign.

Structure and basic markup

  1. Every page has a unique <title> tag, between 50 and 60 characters, built around intent and entity — see the title tag.
  2. Every page has a unique meta description, informative and consistent with the actual content.
  3. Every page contains a single <h1>, with no skipped level in the heading hierarchy.
  4. H2s and H3s in in-depth content are phrased as concrete questions where relevant.
  5. The HTML uses semantic tags (<main>, <article>, <nav>, <header>, <footer>) rather than generic <div>s everywhere.

Content and rendering

  1. Essential text content exists in the raw HTML, without depending exclusively on client-side JavaScript execution.
  2. The order of the HTML in the source code matches the logical reading order, independent of the CSS.
  3. Images carrying information have a descriptive alt attribute.

URLs, duplication, and multilingual

  1. Every page has a canonical tag pointing to an absolute, reachable, and consistent URL.
  2. Pages with parameters (sorting, filters, tracking) canonically point to the clean version of the URL.
  3. No canonical points to a page blocked by robots.txt or returning an error.
  4. Every language version declares its hreflang tags, including one pointing to itself (if applicable).
  5. Hreflang links are reciprocal across all versions.
  6. An x-default is set if the site targets an international audience with no obvious default language.

HTTP statuses

  1. Permanent redirects use a 301 (or 308 if the HTTP method must be preserved), never a 302.
  2. No chain longer than one redirect remains anywhere on the site.
  3. Internal links never point to a URL returning a 404 or an error.

Sharing and structured data

  1. Open Graph tags (og:title, og:description, og:image, og:url) are present and consistent with the page's content.
  2. Relevant Schema.org markup (Organization, Article, Product, FAQPage, BreadcrumbList depending on the page type) is in place and validated.
  3. Data marked up in Schema.org matches exactly what's visible on the page (price, reviews, dates, availability).

Using this checklist in practice

These 20 points aren't a one-shot exercise: revisit them at every redesign, migration, or new page type. Most of the errors listed here are silent — they break nothing visually for a visitor, but progressively degrade how engines and AIs read, trust, and cite your site.

Once these technical foundations are in place, the logical next step is working on the quality and credibility of the content itself: how an LLM chunks your content into usable blocks, how to build the E-E-A-T signals that strengthen the trust granted to your pages, and why citations, figures, and evidence weigh so heavily in how an AI chooses to cite you instead of a competitor.