Technical SEO10 min readFebruary 28, 2025

The Ultimate SEO Audit Checklist for 2025 (37 Checks)

A comprehensive SEO audit checklist covering technical SEO, on-page optimisation, performance, mobile, content quality, and local SEO — with actionable fixes for each issue.

What Is an SEO Audit?

An SEO audit is a systematic review of a website to identify issues that are preventing it from ranking as highly as it could in search engines. A thorough audit covers technical SEO, on-page optimisation, content quality, performance, mobile usability, and more.

This checklist covers 37 checks across 6 categories. You can run it manually, or use a tool like Webstudio's Website Audit to automate all 37 checks in under 30 seconds.

Category 1: On-Page SEO (13 checks)

Check	What to Look For
Title tag	Present, 50–60 chars, contains target keyword
Meta description	Present, 150–160 chars, compelling and keyword-rich
H1 tag	One per page, contains keyword
Heading hierarchy	H2–H6 follow logical structure
Image alt text	All images have descriptive alt attributes
Canonical tag	Present and pointing to the correct URL
Open Graph tags	og:title, og:description, og:image all present
Twitter Card	twitter:card and twitter:title present
Schema markup	Article, FAQ, or LocalBusiness schema detected
XML sitemap	Accessible at /sitemap.xml
Robots.txt	Present and not blocking important pages
Internal linking	At least 3 internal links on key pages
Keyword in URL	Target keyword appears in the URL slug

Category 2: Technical Performance (8 checks)

Check	What to Look For
Page load time	Under 3 seconds (ideally under 1.5s)
Page size	HTML under 100KB
HTTPS	Valid SSL certificate, no mixed content
HTTP redirect	HTTP automatically redirects to HTTPS
Gzip/Brotli	Compression enabled on the server
Browser caching	Cache-Control headers present
Render-blocking JS	No scripts in `<head>` blocking render
Image optimisation	No uncompressed images over 200KB

Category 3: Mobile & UX (8 checks)

Check	What to Look For
Viewport meta tag	`<meta name="viewport">` present
Mobile-friendly	Viewport configured correctly
Font size	Base font 14px or larger
Tap targets	Buttons and links large enough to tap
Custom 404 page	Returns HTTP 404 (not 200)
Navigation	`<nav>` element present
Contact information	Phone or email visible on page
Social media links	Links to social profiles present

Category 4: Content Quality (5 checks)

Check	What to Look For
Word count	Homepage has 300+ words
Blog/news section	Content hub present
Content freshness	Last-Modified header or recent date
Readability	Average sentence length under 20 words
Duplicate content	Title and description are unique

Category 5: Technical Health (6 checks)

Check	What to Look For
Broken links	All links on homepage return 200
Redirect chains	No 301→301 chains
www consistency	www and non-www redirect to one canonical version
Favicon	favicon.ico present
HTML validity	No obvious structural errors
Iframe usage	No iframes (security and crawlability concern)

Category 6: Trust & Compliance (5 checks)

Check	What to Look For
Privacy policy	Link to privacy policy present
Cookie notice	GDPR/cookie consent banner detected
Terms & conditions	Link to T&Cs present
SSL padlock	HTTPS with valid certificate
Copyright notice	Copyright year in footer

How to Prioritise Fixes

Not all issues are equal. Use this priority framework:

**Critical (fix immediately):** Broken HTTPS, robots.txt blocking crawlers, missing H1, no sitemap
**High impact:** Missing meta descriptions, slow page load, no schema markup, broken links
**Medium impact:** Missing OG tags, no blog section, poor readability
**Low impact:** Missing Twitter Card, iframe usage, copyright notice

Run Webstudio's Website Audit to automatically score all 37 checks and get a prioritised fix list with specific recommendations for each issue.