Technical SEO Checklist: What to Fix First, in Order of Impact

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What a technical SEO checklist covers (and what it does not)

Technical SEO is the plumbing of your website. Your content can be excellent, but if Google cannot fetch a page, or fetches the wrong version of it, that page will never rank. A technical checklist answers three questions, in this order: can search engines reach the page, can they understand it, and is the page pleasant to use?

Google itself keeps the bar low. Its Search Essentials technical requirements list only three conditions for a page to be eligible for indexing: Googlebot is not blocked, the page returns an HTTP 200 (success) status code, and the page has indexable content. Everything else on this list is about doing those three things cleanly, at scale, without wasting Google's attention.

What a technical checklist does not cover: keyword choice, the quality of your writing, or backlinks. Those belong to on-page SEO and link building. If you want the full picture of how an audit is scored and reported, our guide to the technical SEO audit goes deeper on method. This article takes a different angle: it ranks every check by impact, so a busy owner knows what to fix first and what can wait.

Priority	What it protects	Typical checks	What happens if you skip it
1. Blocking	Indexing	robots.txt, noindex tags, 4xx and 5xx errors, HTTPS	Pages disappear from Google entirely
2. Wasteful	Crawl efficiency	Redirect chains, duplicates, canonicals, sitemap, broken links	Google indexes the wrong version or ignores new pages
3. Experience	Rankings and conversions	Core Web Vitals, mobile layout, structured data	You rank lower than you could and visitors leave
4. AI readiness	Visibility in ChatGPT, Gemini, Perplexity	AI crawler access, content in raw HTML, clear entities	AI assistants cite your competitors instead of you

The one-hour first pass: start here

You do not need to be a developer to run this first pass. You need access to Google Search Console, a crawler (free versions are enough for small sites), and a list of your ten most important pages: home page, main service or product pages, pricing, contact.

Write down what you find in a simple table: URL, problem, priority, owner, date fixed. This log is what turns a one-off audit into a habit. If you want help choosing a crawler, our comparison of the best technical SEO tools ranks them by the job they do.

Priority 1: remove everything that blocks indexing

These checks come first because a single mistake can remove a whole section of your site from Google. They are also usually quick to fix once found.

robots.txt does not block important pages

The robots.txt file tells crawlers which folders they may visit. A leftover line such as Disallow: / from a staging site is one of the most common causes of a site vanishing after a redesign. Check that your product, service and blog folders are allowed, and that CSS and JavaScript files are not blocked, since Google needs them to render the page. You can validate the file in seconds with our robots.txt checker, and if Search Console already shows the warning, our guide to Blocked by robots.txt explains each fix.

No stray noindex tags

A noindex meta tag or HTTP header tells Google to drop a page. It is useful on thank-you pages, internal search results and login screens. It is a disaster on your pricing page. Filter your crawl export by "noindex" and confirm every page in that list is meant to be hidden.

Key pages return a 200 status code

Every important URL should answer with a 200 code. Pages that return 404 (not found) or 5xx (server error) cannot be indexed. Server errors deserve special attention: if they repeat, Google slows down its visits to protect your server. Pages that look empty but return 200, called soft 404s, are another trap covered in our soft 404 guide.

One secure version of the site

Your site can be reached in four ways: with or without "www", with "http" or "https". Only one should answer; the other three should redirect to it permanently. Type each variant in your browser and check where you land. Our guide to HTTPS and SEO covers safe migration if you are still partly on http.

Priority 2: stop wasting Google's attention

Once nothing is blocked, the next goal is to make every crawl count. Google does not visit every URL every day. Each duplicate, chain or dead link it follows is a visit not spent on your new content.

Redirects go straight to the final page

A redirect chain is when page A sends to B, which sends to C. Each hop slows users down and dilutes signals. Replace every chain with one direct permanent redirect (301) from the old URL to the final one, and update internal links so they point to the final URL directly. Follow any URL's path with our redirect checker, and see our complete guide to SEO redirects for when to use 301, 302, 307 or 308.

Duplicates point to one canonical URL

The same page often exists under several addresses: with tracking parameters, with filters, with or without a trailing slash. The canonical tag tells Google which version is the reference. Check that each important page has a canonical pointing to itself, and that Google agrees: in URL Inspection, compare "User-declared canonical" with "Google-selected canonical". Our free canonical checker shows where any page's canonical points.

The XML sitemap lists only pages you want indexed

Your sitemap is a list you hand to Google. It should contain only live, indexable, canonical URLs that return 200. According to Google's sitemap documentation, each file is limited to 50MB uncompressed or 50000 URLs, must use full absolute URLs, and should list the version you want shown in results. Submit it in Search Console and compare "submitted" with "indexed". Our step-by-step guide shows how to create a sitemap, and the sitemap checker validates the file.

No broken internal links, no orphan pages

Internal links are how both visitors and crawlers move through your site. Fix every internal link that leads to a 404, and make sure each important page receives at least a few links from related pages. A page with no internal links pointing to it (an orphan page) is often found late, or not at all. Our guide to site architecture for SEO explains how to keep key pages close to the home page.

Priority 3: make pages fast, stable and mobile-friendly

Speed and mobile usability rarely remove a page from Google, but they influence how well it ranks and, above all, whether visitors stay. Google's Core Web Vitals documentation sets three targets: Largest Contentful Paint (LCP, the time to show the main content) within 2.5 seconds, Interaction to Next Paint (INP, how fast the page reacts to a tap or click) under 200 milliseconds, and Cumulative Layout Shift (CLS, how much the layout jumps) under 0.1. Google says these scores align with what its core ranking systems seek to reward, without saying how much they weigh.

Most sites still miss at least one target. The 2024 performance chapter of the HTTP Archive's Web Almanac measured mobile websites against each threshold:

Loading is the weakest point, so start there. The usual fixes are simple to brief to a developer or agency:

• Compress and resize images, serve them in a modern format, and give the main image priority instead of lazy-loading it.
• Remove scripts you no longer use: old chat widgets, abandoned tracking tags, unused sliders.
• Reserve space for images, ads and embeds with fixed dimensions, so the layout does not jump.
• Test on a real phone: buttons large enough to tap, no pop-up covering the content, the same content as on desktop.

Our guide to PageSpeed Insights explains how to read the report and ignore the noise, and the glossary entry on Core Web Vitals covers each metric in plain words.

Structured data where it matches the page

Structured data (schema markup in JSON-LD format) describes your page to machines: this is a product, this is its price, this is the company behind it. Add it only where it truthfully matches visible content: Organization on the home page, Product on product pages, Article on blog posts, LocalBusiness for a shop. Validate it with our structured data validator before publishing.

Priority 4: open the door to AI assistants

A growing share of searches now ends in an answer from ChatGPT, Gemini, Claude or Perplexity rather than a list of links. These assistants rely on their own crawlers, and a site that is perfect for Google can still be invisible to them. Three checks matter most:

• AI crawlers are not blocked by accident. Many robots.txt files and firewall rules block bots such as GPTBot or PerplexityBot by default. Decide deliberately which ones you allow; our guide to robots.txt for AI crawlers lists them.
• Your main content is in the raw HTML. Many AI crawlers do not run JavaScript. If your text only appears after scripts load, they see an empty page. Our JavaScript SEO guide shows how to check.
• Your brand facts are clear and consistent. Company name, what you sell, where you operate: the same on your site, your structured data and your profiles elsewhere.

For the full list, see our technical GEO checklist. Once the fixes are live, you need to know whether they work. Sorank's GEO / SEO dashboard shows your Google traffic and your visibility in AI assistants in one view, so you can see the effect of each fix without switching tools.

Common technical SEO mistakes

These are the errors we see most often on small and mid-size business sites. Most of them come from a redesign, a platform change or a plugin installed without checking.

The last one is the most costly. Websites drift: a plugin update adds a noindex, a new page template forgets the canonical, an editor deletes a page that had backlinks. A short monthly check catches these before they cost traffic.

Your technical SEO checklist to keep

Copy this list into your project tool and tick it once a month, then after every redesign, migration or platform change. Items are in priority order.

If you only have time for one thing today, do the first two lines: open Search Console and inspect your ten most important pages. If one of them is not on Google, you have found your priority for the week. If they all are, run a crawl and work down the list. Our free broken link checker is a quick way to start on any page.