Technical SEO isn't glamorous. But it's the foundation that everything else — content, links, brand — sits on. A site with great content and poor technical health will always underperform a technically clean site, no matter how good the writing is.
This is the checklist we use internally before launching any client site. Use it to audit your own.
Crawlability and Indexability
Robots.txt — Check that your robots.txt file isn't accidentally blocking important pages or directories. A common mistake is disallowing / (the entire site) in a staging configuration that makes it to production.
XML Sitemap — Your sitemap should list every page you want indexed, be submitted to Google Search Console, and be referenced in your robots.txt file. It should not include pages with noindex tags or redirect URLs.
Noindex tags — Audit for unintentional noindex meta tags. These are often added during development and forgotten. A single noindex on your homepage will remove it from search results entirely.
Canonical tags — Every page should have a self-referencing canonical tag. Pages with pagination, filtering, or similar content should use canonicals to point to the primary version.
Redirect chains — Redirect chains (A → B → C) slow down crawling and dilute link equity. Audit for chains and update them to direct 301 redirects (A → C).
Core Web Vitals
Google's Core Web Vitals measure real-world user experience. As of 2024, they are a confirmed ranking factor.
Largest Contentful Paint (LCP) — Should be under 2.5 seconds. The most common causes of poor LCP: unoptimised hero images, slow server response times, and render-blocking resources.
Cumulative Layout Shift (CLS) — Should be under 0.1. Common causes: images without defined dimensions, dynamically injected content, and web fonts loading without size hints.
Interaction to Next Paint (INP) — Should be under 200ms. This replaced FID in 2024 and measures overall responsiveness throughout the page lifecycle.
How to check: Use PageSpeed Insights for field data, and Lighthouse for lab data. Both are free.
On-Page Elements
Title tags — Unique, under 60 characters, front-loaded with primary keyword. Never duplicated across pages.
Meta descriptions — 120–160 characters. Unique for every page. Not a direct ranking factor, but heavily influences click-through rate from search results.
Heading hierarchy — One H1 per page, containing the primary keyword. H2s for main sections, H3s for subsections. Never skip levels (don't jump from H1 to H4).
Image optimisation — Every image should have a descriptive alt attribute, be served in a modern format (WebP or AVIF), and be appropriately sized. Images are usually the biggest contributor to poor LCP scores.
Internal linking — Every important page should have relevant internal links from other pages. Use descriptive anchor text (not "click here").
Structured Data
Structured data tells Google what your content is, helping it appear in rich results.
Organisation schema — Add to your homepage. Includes your business name, logo, contact information, and social profiles.
Article schema — Add to all blog posts. Includes headline, author, publish date, and modified date.
LocalBusiness schema — If you have a physical location, this helps with local search rankings and Google Business Profile integration.
BreadcrumbList schema — Helps Google understand your site structure and can display breadcrumbs in search results.
Security and HTTPS
HTTPS everywhere — All pages should be served over HTTPS. Non-HTTPS pages receive a ranking penalty and trigger browser security warnings.
Security headers — X-Content-Type-Options, X-Frame-Options, and Content-Security-Policy headers protect your users and signal to Google that you take security seriously.
Mixed content — If any resources (images, scripts, stylesheets) are loaded over HTTP on an HTTPS page, browsers will block them and rankings can be affected.
Mobile Usability
Mobile-first indexing — Google predominantly uses the mobile version of your site for indexing. If your mobile experience is worse than desktop, your rankings suffer.
Tap target sizes — Buttons and links should be at least 48x48px to be easily tappable on mobile.
Viewport meta tag — Every page needs the correct viewport meta tag.
Font sizes — Body text should be at least 16px on mobile. Smaller text forces users to zoom, increasing your bounce rate.
This is a condensed version of the 40+ checks we run in our free website audit. If you'd like us to run it on your site and send you a personalised report, get your free audit here.