Key takeaways
- Technical SEO is the work that makes a site reachable, renderable and storable by a search engine, covering crawling, indexation, rendering, page speed and structured data, and it is the layer content and links sit on top of rather than a substitute for either.
- Crawlability is whether a search engine can reach a page at all, while indexation is whether it decides the crawled page is worth storing, and the two fail for different reasons so they need separate fixes.
- Run the full technical SEO checklist quarterly and a lighter crawl-and-index pass after every significant deploy, because a regression caught within a day of a release costs an hour and the same regression found in a quarterly review usually becomes a recovery project.
- A site crawler, Search Console, the Rich Results Test and PageSpeed Insights cover a first audit on a mid-size site, so tooling is rarely the thing that blocks the work.
- Technical health carries into AI search as well, because the ChatGPT and Perplexity crawlers do not execute JavaScript, so anything rendered only in the browser is invisible to them even when Google can see it.
A technical SEO checklist is the set of crawlability, indexation, rendering, and site-health checks you run to make sure search engines can reach and store every page that matters. Content and links do the ranking, but if Googlebot cannot crawl a page, or it renders as an empty shell, none of that counts. This checklist covers the items we run on every quarterly technical review, grouped so a developer or in-house marketer can work through them in order.
If you would rather hand the whole review over, this is ordinary technical SEO services work and somebody else can run the list and return a prioritized set of fixes. Either way, what follows is complete enough to run yourself.
- What is technical SEO? It is the work that helps search engines reach, render, understand, index, and keep important pages stable over time.
Crawlability
Start with what search engines can and cannot reach. Open your robots.txt and confirm you are not blocking directories that contain indexable pages. A single stray Disallow rule is enough to strip thousands of URLs from the index. Check that your XML sitemap includes only canonical, indexable, 200 status URLs, and that it is referenced from robots.txt and submitted in Search Console. Crawl the site with Screaming Frog or Sitebulb and look for 4xx and 5xx status codes, redirect chains longer than one hop, and internal links pointing to redirected URLs. Fix redirect chains at the source rather than adding another hop.
Indexation
Pull the Pages report in Search Console and read every reason listed under Not indexed. The common culprits are Discovered currently not indexed, Crawled currently not indexed, Duplicate without user-selected canonical, and Alternate page with proper canonical tag. Each has a different fix, so do not treat them as one problem. Confirm every important page returns a self-referencing canonical, uses index in the robots meta tag, and is not blocked by an X-Robots-Tag response header. Prune thin or duplicate URLs with noindex or 410, do not leave them to compete for crawl. Watch that faceted navigation and internal search results are not generating an unbounded set of URLs, which is a common way a 200-page site balloons to 50,000 crawlable URLs.
Site architecture
Every important page should sit within three clicks of the homepage. Group content into topical hubs with clear parent and child relationships, and use breadcrumbs on every template. Internal links should use descriptive anchor text and point to the canonical URL rather than a redirecting one. Audit for orphan pages, which are pages that receive no internal links, and either link them in or remove them. A page with zero internal links is a page Google struggles to value, no matter how good the content is.
Rendering
If your site uses JavaScript to render primary content, test how Googlebot sees it. Use the URL Inspection tool in Search Console and compare the rendered HTML against the source HTML. Critical copy, headings, internal links, and structured data must appear in the rendered DOM. Remember that ChatGPT and Perplexity crawlers do not run JavaScript at all in 2026, so content injected on the client is invisible to AI search. For deeper coverage of frameworks and rendering patterns, see our JavaScript SEO.
Core Web Vitals
Pull field data from the Chrome UX Report and check LCP, INP, and CLS on your key templates. Google uses the 75th percentile of real-user data as the ranking signal, so lab scores are only a debugging aid. Aim for LCP under 2.5 seconds, INP under 200 milliseconds, and CLS under 0.1. Because CrUX uses a rolling 28-day window, expect a lag between a fix shipping and the field data reflecting it. Our technical SEO services cover the fixes that hold up in production.
Mobile and internationalization
Confirm the mobile version of every template contains the same primary content, headings, structured data, and internal links as the desktop version, because Google indexes the mobile page. A mobile layout that hides content behind a menu or drops a section entirely will be indexed with that content missing. If you serve multiple languages or regions, check that hreflang tags are reciprocal, use valid language and region codes, and point to canonical, indexable URLs. Broken hreflang is one of the most common causes of the wrong country version outranking the right one.
Structured data
Deploy JSON-LD for the entity types that match your content, including Organization, Article, Product, FAQ, Breadcrumb, and LocalBusiness where relevant. Validate every template in the Rich Results Test and monitor the Enhancements reports in Search Console for errors introduced by CMS updates. A theme update that strips a required property can cost you rich results across an entire template overnight, so treat structured data as something to monitor, not set once.
HTTPS, security, and headers
Confirm every URL serves over HTTPS with a valid certificate. Check that HTTP versions issue a 301 to HTTPS, not a 302. Review response headers for HSTS, a sensible Content Security Policy, and correct Cache-Control on static assets. Mixed content warnings and expired certificates still cause crawl and trust issues that show up in rankings. Set a calendar reminder 30 days before certificate expiry, because a lapsed certificate can take a site offline for crawlers within hours.
Log file analysis
Once a quarter, pull raw server logs and filter for verified Googlebot requests. Look at the ratio of crawls that hit important pages versus parameter URLs, pagination, or old redirects. If crawl is being wasted, tighten robots directives and internal linking. On a large site you often find 30% to 50% of crawl budget spent on URLs that should not be crawlable at all. Verify Googlebot by reverse DNS rather than trusting the user agent, since scrapers routinely spoof it. Also check crawl frequency against publishing cadence: if you publish daily but Googlebot visits your key section weekly, that gap is a discoverability problem worth solving with fresher internal links and a cleaner sitemap. For context on when this matters, read technical SEO services.
Ongoing monitoring
Set up alerts for Search Console coverage changes, sudden ranking drops, and Core Web Vitals regressions. Every deploy should trigger a post-release crawl to compare technical state before and after. Regressions caught within a day are cheap to fix. Regressions caught in a quarterly review are usually a recovery project that costs weeks of lost traffic.
Keep a short change log tied to your search metrics so that when traffic moves you can line the change up against a deploy, a Google update, or a seasonal pattern. Without that record, every drop turns into a guessing exercise. Pair automated alerts with a human eye on the Search Console Pages report once a week, because coverage problems often build slowly and slip under a threshold-based alert until a large share of URLs has already fallen out of the index.
If you are running a replatform or URL restructure alongside this work, pair this checklist with our SEO migration checklist so nothing slips during launch.
Whoever runs it on a recurring cadence, in-house or outside, the deliverable that makes the difference is the same: developer-ready specs, validation against staging, and post-deploy monitoring, so a regression gets caught before it costs rankings.
Related terms
Related technical audit searches include how to conduct a technical SEO site audit, SEO tech audit checklist, SEO technical audit checklist, SEO technical checklist, and technical SEO audit checklist.
Related searches also include technical SEO ranking factors, technical SEO tips, and which technical SEO issues are most important.
Frequently Asked Questions
How often should the full review be run?
Run the full technical SEO checklist quarterly and a lighter crawl-and-index pass after every significant deploy. High-change sites, such as large e-commerce catalogs, benefit from monthly crawls. The principle is to catch regressions within a day of a release rather than in a quarterly review, because an issue caught early costs an hour and the same issue caught late can cost weeks of lost traffic to recover.
What tools do I need for a technical SEO audit?
A site crawler such as Screaming Frog or Sitebulb, Google Search Console, the Rich Results Test, PageSpeed Insights, and access to raw server logs cover the core. Screaming Frog is free for up to 500 URLs. For log analysis and large-scale monitoring you may add a paid platform, but you can complete a thorough first audit on a mid-size site with free tools alone.
What is the difference between crawlability and indexation?
Crawlability is whether search engines can reach a page by following links and reading sitemaps. Indexation is whether Google decides that crawled page is worth storing and ranking. A page can be perfectly crawlable yet excluded from the index because of a canonical tag, a robots directive, or duplicate detection. The checklist treats them as separate sections because they have different fixes.
Does technical SEO affect AI search visibility?
Yes. AI crawlers from ChatGPT and Perplexity do not execute JavaScript in 2026, so content that renders only on the client is invisible to them. Clean crawlability, server-side or static rendering, and structured data all make your pages easier for generative engines to read and cite. The same technical health that supports Google rankings supports AI search visibility.
How do I know if my crawl budget is being wasted?
Pull raw server logs, filter for verified Googlebot, and look at which URLs it spends time on. If a large share of crawls hit parameter URLs, pagination, faceted navigation, or old redirects instead of your important pages, crawl is being wasted. Tighten robots directives, fix internal links to point at canonical URLs, and remove links to redirected pages to redirect that budget.
What is technical SEO?
Technical SEO is the work that helps search engines crawl, render, index, and understand a site. It includes redirects, indexation rules, internal links, structured data, page speed, mobile rendering, security, and monitoring.