The Technical SEO Checklist I Run Before Every Client Engagement

Before I write a single content brief for a new client, I work through the same technical pass. The reason is simple: content and link work compound, but only on top of pages that search engines can actually reach, render, index, and load quickly. Skip that layer and you spend months producing pages that never get a fair evaluation.

The checklist below is grouped the way search engines process a page — crawl, index, render, then experience. Within each group I have noted what the check catches and the usual fix, so you can run it yourself rather than just tick boxes.

1. Crawl

• robots.txt sanity. Confirm nothing important is disallowed, and that CSS and JS paths are crawlable — blocking them breaks rendering. Fix: narrow the disallow rules.
• Sitemap accuracy. Every URL should return 200, be canonical, and be absolute. Redirects, 404s, and noindexed URLs inside a sitemap waste crawl budget and cause fetch warnings in Search Console.
• Internal link reachability. Any page that only exists in the sitemap, with no internal link pointing at it, is effectively an orphan. Fix: link it from a relevant hub page.
• Redirect chains and loops. Every hop loses a little and slows crawling. Fix: point redirects straight at the final destination.
• Host and protocol consolidation. One canonical host, HTTPS only, one trailing-slash convention. Everything else should redirect once to it.
• Server response codes on error paths. Missing pages must return 404 or 410, not a 200 with a "not found" message. Soft 404s keep dead URLs in the index.
• Faceted and parameter URLs. Filter and sort parameters can generate thousands of near-duplicate URLs. Fix: canonicalise to the clean URL, and avoid linking to parameterised variants internally.

2. Index

• Indexation gap. Compare pages you want indexed against Search Console's Pages report. Persistent "Crawled — currently not indexed" clusters usually signal thin or duplicate content, not a technical bug.
• Canonical correctness. Every page should self-reference unless it is a deliberate duplicate. Cross-domain or homepage-pointing canonicals on inner pages are one of the most damaging mistakes I find, because they hand every page's signals somewhere else.
• Accidental noindex. Check both the meta tag and the X-Robots-Tag header. Staging noindex directives surviving a launch is a classic.
• Duplicate titles and descriptions. Usually a template problem rather than a writing problem. Fix the template variables and hundreds of pages improve at once.
• Pagination handling. Paginated pages should be crawlable, self-canonical, and linked with real anchors rather than JavaScript-only controls.
• Language and region signals. If the site has multiple locales, hreflang must be reciprocal and reference indexable URLs only.

3. Render

• Main content in the initial HTML. View source, not the inspector. If the body copy, headings, and internal links only appear after JavaScript runs, treat that as a priority fix — server rendering or static generation.
• Blocked resources. Use the URL Inspection rendered-HTML view to confirm no critical CSS or JS is blocked or failing.
• Real anchors for navigation. Click handlers on divs are not links. Navigation and pagination need <a href>.
• Heading structure. One H1 per page, headings that describe the section beneath them. This matters more now that answer engines extract passages by heading.
• Structured data validity. Schema should match what is visible on the page and parse without errors. Invalid JSON-LD is ignored silently.
• Image and media semantics. Descriptive alt text, real dimensions, and no content that exists only inside an image.

4. Experience and Core Web Vitals

• Field data first. Start with the Core Web Vitals report in Search Console. Lab scores are diagnostic; field data is what gets assessed.
• LCP element identification. Find the actual largest element, then preload it, serve it in a modern format, and never lazy-load it.
• Interaction responsiveness. Long tasks from third-party scripts are the usual cause. Defer, remove, or load them on interaction.
• Layout stability. Reserve space for images, ads, and embeds; avoid injecting banners above existing content.
• Mobile parity. The mobile page must contain the same content, links, and structured data as desktop.
• Caching and compression. Long cache lifetimes on static assets and compression enabled — cheap wins that show up on every page.

How I Prioritise the Findings

Not every issue deserves dev time. I sort findings into three buckets: things that block crawling, indexing, or rendering go first, because nothing else works until they are cleared. Things that split or misdirect signals — canonicals, duplicates, redirect chains — go second, since they usually deliver the largest gain per hour of work. Everything else, including most performance micro-optimisations, goes third and gets scheduled rather than escalated.

The written deliverable matters as much as the audit. Each item gets a one-line problem statement, the affected URL pattern, the fix, and who owns it. A list of 200 unranked issues gets ignored; a list of eight ranked ones gets shipped.

Where This Connects to AEO and GEO

Everything above is also the foundation for AI search visibility. Retrieval systems that feed generative answers need clean, crawlable HTML with clear headings and valid structured data. If you are working on why your brand is missing from ChatGPT search, the technical layer is where that work starts — not with the markup you add last.

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