Technical SEO
SEO Site Audit Checklist 2026: The Complete 47-Point Technical Audit Guide
An SEO site audit is a structured review of everything that can prevent a page from being crawled, indexed, understood or ranked. A good audit ends with a prioritised fix list, not a score.
This checklist covers 47 checks in seven categories, ordered by impact. Work top to bottom: a crawlability problem makes every content improvement below it irrelevant.
Free tools used in this guide
Category 1 — Crawlability and Indexation (8 checks)
- robots.txt exists, returns 200 and does not block CSS or JS
- No accidental noindex in the meta robots tag or X-Robots-Tag header
- XML sitemap exists, is referenced in robots.txt and contains only canonical 200 URLs
- Canonical tag present and self-referencing on every indexable page
- No redirect chains longer than one hop to the final URL
- No orphan pages — every important URL is linked from at least one other page
- Pagination and faceted URLs controlled to avoid index bloat
- AI citation bots (OAI-SearchBot, PerplexityBot, ClaudeBot, Google-Extended) explicitly allowed
Category 2 — On-Page Signals (9 checks)
- Unique title tag between 30 and 60 characters containing the primary keyword
- Meta description between 70 and 160 characters written for click-through, not stuffing
- Exactly one H1 that states the page topic in plain language
- Heading hierarchy without level skips (H2 → H4)
- Primary keyword present in the first 100 words
- Descriptive, lowercase, hyphenated URL slug
- Internal links with descriptive anchor text, never 'click here'
- Outbound links to authoritative sources where claims need support
- Open Graph and Twitter Card tags complete for social and AI preview surfaces
Category 3 — Content Quality (7 checks)
- The main query is answered directly in the first 200 words
- Word count matches search intent rather than an arbitrary target
- Paragraphs limited to three sentences for extractability
- Original data, examples or screenshots that no competitor can copy
- Named author with credentials and a visible last-updated date
- No duplicated or near-duplicated blocks across templates
- Readability appropriate for the audience — Flesch 50+ for general topics
Category 4 — Structured Data (6 checks)
- Valid JSON-LD present in the head of every important template
- The @type matches the page purpose (Article, Product, FAQPage, SoftwareApplication)
- All required properties for the chosen type are populated
- FAQPage markup mirrors visible on-page questions and answers
- BreadcrumbList markup matches the visible breadcrumb trail
- Organization and WebSite markup on the homepage with sameAs profiles
Category 5 — Core Web Vitals and Performance (7 checks)
- Largest Contentful Paint under 2.5 seconds on mobile
- Interaction to Next Paint under 200 milliseconds
- Cumulative Layout Shift under 0.1
- HTML document under 150 KB where possible
- Images served in modern formats with explicit width and height
- Render-blocking scripts deferred and unused CSS removed
- Compression and long-lived caching headers enabled
Category 6 — Mobile and Security (5 checks)
- Responsive viewport meta tag with width=device-width
- No horizontal scrolling and no fixed-width elements
- Tap targets at least 48 px with adequate spacing
- HTTPS everywhere with HSTS and no mixed content references
- Baseline security headers: CSP, X-Content-Type-Options, Referrer-Policy
Category 7 — Authority and AI Readiness (5 checks)
- llms.txt published at the domain root
- About, Contact, Privacy and Terms pages present and genuinely informative
- Author pages that establish real expertise (E-E-A-T)
- Backlink profile reviewed for toxic or sitewide spam links
- Entity consistency: identical brand name, address and profiles across the web
Frequently Asked Questions
How often should I run a full SEO audit?
Run a complete audit quarterly, a lightweight technical audit monthly, and a targeted audit after every migration, redesign or Google core update.
What should I fix first after an audit?
Fix in this order: indexation blockers, then broken canonicals and redirects, then Core Web Vitals failures, then on-page and content issues. Anything that stops crawling outranks everything else.
Do I need a paid crawler to audit a site?
Not for a single site. Free tools cover meta tags, headings, schema, robots, sitemaps, speed and AI readiness. Paid crawlers matter mainly above roughly ten thousand URLs.
How long until audit fixes affect rankings?
Technical fixes such as removing a noindex can take effect within days. Content and authority changes typically show up over four to twelve weeks.
What is the difference between a technical audit and a content audit?
A technical audit asks whether search engines can reach and understand the page. A content audit asks whether the page deserves to win the query once they can.