SEO Audit Checklist: 40 Points That Cover 90% of Issues

A full SEO audit has three sections: technical, on-page, and off-page. Most audits I see either go too deep on technical and ignore content, or focus on on-page and barely touch off-page. This checklist covers all three. It's not exhaustive — a 200-point audit exists, but 90% of issues fall into these 40 checks. I've prioritized by impact within each section.

Before you start: you'll need access to Google Search Console, Google Analytics (or an alternative), a crawl tool (Screaming Frog is the standard, Sitebulb is also good), and ideally a backlink tool like Ahrefs or Semrush. Some checks can be done manually; others need data.

Technical SEO Checks (15 Points)

1. HTTPS implementation. Is the entire site served over HTTPS? Check that HTTP URLs redirect to HTTPS (301, not 302). Check that internal links use HTTPS. A mixed content warning (HTTPS page loading HTTP resources) can suppress the security indicator and occasionally affects crawling. Run your domain through SSL Labs for a full certificate check.
2. Canonical tags. Every indexable page should have a self-referencing canonical tag. Check for: missing canonicals, canonical tags pointing to incorrect URLs, conflicting canonicals (page A canonicals to page B which canonicals back to page A), and canonical tags on pages that also have a noindex. Screaming Frog will crawl all canonicals and flag conflicts.
3. Robots.txt. Verify it exists at yourdomain.com/robots.txt. Check that it's not blocking important pages, CSS files, JavaScript files, or image directories. Confirm the Sitemap URL is listed. Use GSC's URL inspection to test specific URLs.
4. XML sitemap. Does it exist? Is it submitted to GSC? Does it include all indexable pages and only indexable pages (no noindex pages, 4xx pages, or redirect pages in the sitemap)? Is it up to date? For large sites, check that it's split into sub-sitemaps and a sitemap index file.
5. Page speed and Core Web Vitals. Run your main templates (homepage, category, product/article, contact) through PageSpeed Insights. Focus on LCP (should be under 2.5 seconds), CLS (under 0.1), and INP (under 200ms). Check GSC's Core Web Vitals report for field data — lab data and field data often differ. LCP issues are usually unoptimized images or slow server response. CLS issues are usually unsized images or dynamic content inserting above existing content.
6. Mobile-friendliness. Google indexes the mobile version of your site. Use the Mobile-Friendly Test in GSC or the URL Inspection tool. Check for: text too small to read, interactive elements too close together, content wider than the screen, horizontal scrolling. Test on an actual phone, not just browser DevTools.
7. Crawl errors. Check GSC's Coverage report for server errors (5xx), not-found errors (404), and crawled-but-not-indexed pages. A spike in server errors indicates hosting instability. A large number of 404s usually means poor redirect management or link rot. "Crawled but not indexed" requires investigation — Google is seeing the page but choosing not to index it.
8. Redirect chains and loops. A redirect chain is A redirects to B which redirects to C. Each hop loses a small amount of PageRank. Chains of 3+ hops are worth fixing. A redirect loop is A redirects to B which redirects back to A — this causes browsers and crawlers to give up entirely. Screaming Frog identifies both.
9. Structured data validity. Use Google's Rich Results Test on your key page templates. Check for errors (structured data with errors doesn't generate rich results) and warnings (minor issues that reduce reliability). Validate against Google's documentation for each schema type. Common issues: missing required fields, incorrect property values, implementing schema types Google doesn't support.
10. Hreflang implementation (multi-language/region sites). If your site serves multiple languages or regions, check hreflang tags for: bidirectional implementation (every hreflang alternate page must include return tags), correct language codes (en, en-US, en-GB — not "english" or "EN"), and x-default tag for language selectors. Hreflang errors are among the most common technical issues on international sites.
11. Duplicate content. Use Screaming Frog's duplicate content report to find pages with identical or near-identical content. Common causes: www vs. non-www (should 301 to one canonical version), trailing slash variations (/page and /page/), URL parameter variations, printer-friendly page versions. The fix is canonical tags or 301 redirects.
12. Thin content. Filter your crawl results for pages under 300 words. Not every page needs to be 1,500 words — a contact page is fine at 100 words. But thin category pages, stub blog posts, or product pages with 50-word descriptions are ranking liabilities. Either expand them or noindex them.
13. URL structure. Check for: URLs containing session IDs (these create duplicate content at massive scale), parameters in URLs that should be handled differently, unnecessarily deep URL paths, and special characters or spaces encoded in URLs. Clean, descriptive URLs that use hyphens and don't contain parameters are the standard to aim for.
14. Internal 404s. These are links within your own site pointing to pages that no longer exist. They waste crawl budget, create a poor user experience, and pass PageRank to a dead end. Screaming Frog finds them in one crawl. Fix by updating the link or setting up a redirect for the missing page.
15. Server response time. Time to first byte (TTFB) should be under 800ms, ideally under 200ms. Slow TTFB means slow everything else. Check with GTmetrix or WebPageTest. Common causes: cheap shared hosting, unoptimized database queries, no page caching, missing CDN. This is infrastructure, not SEO — but it affects every ranking signal that depends on page speed.

On-Page SEO Checks (15 Points)

1. Title tags. Check for: missing title tags, duplicate title tags (GSC's Coverage report flags these), title tags over 60 characters (get truncated in results), title tags missing the primary keyword, and title tags that don't match the page's actual content. Every page should have a unique, descriptive title tag with the primary keyword toward the front.
2. Meta descriptions. They don't directly affect rankings, but they affect click-through rate. Check for: missing meta descriptions (Google writes its own, often not great), duplicate descriptions, descriptions over 160 characters, and descriptions that don't match the page's content. A good meta description acts like ad copy — it should give the searcher a reason to click.
3. H1 tags. Every page should have exactly one H1 tag. It should contain the primary keyword and describe the page's main topic. Common issues: multiple H1s (common on CMS platforms where the site name is coded as H1), missing H1, H1 that doesn't match the title tag topic, H1 that's an image with no alt text.
4. H2-H6 hierarchy. Heading structure should be hierarchical and logical. H2 for main section headers, H3 for subsections within H2s, and so on. Common mistakes: jumping from H1 to H4, using headings purely for visual styling, no headings below H1 on long-form content. Headings help both users (navigation, skimming) and crawlers (content structure understanding).
5. Image alt text. Every content image should have descriptive alt text. Check for: completely missing alt text, alt text that's just the file name (image1.jpg), keyword-stuffed alt text, and decorative images that should have empty alt text (alt="") rather than no alt attribute. Screaming Frog has a dedicated images report.
6. Keyword in URL. The URL slug should include the primary keyword for the page. Short, descriptive slugs perform better than automatically generated numeric IDs or overly long slugs. Compare /blog/keyword-research-guide versus /blog/post?id=47281. The slug doesn't need to match the title exactly — trim stop words and keep the core keyword.
7. Content depth and quality. Compare your page's word count and topic coverage against the top 3-5 ranking results for your target keyword. If they're averaging 2,000 words with subtopics you haven't covered, you have a content gap. Tools like Clearscope, Surfer, or manual analysis can identify missing topics. More words is not automatically better — but inadequate coverage is a real ranking barrier.
8. Internal links. Every important page on your site should have internal links pointing to it from other pages. Check for: orphan pages (no internal links pointing to them), pages with few internal links relative to their importance, and anchor text distribution in internal links (use descriptive, keyword-adjacent text rather than "click here"). GSC's link report shows internal links per page.
9. Outbound link quality. Linking out to authoritative, relevant sources improves content quality signals. Check that you're not linking to spammy, low-quality, or irrelevant sites. Check for broken outbound links (Screaming Frog will find these). External links to low-trust domains can be a quality signal concern.
10. Content freshness. For time-sensitive topics, content age matters. Check your key pages for outdated statistics, old dates, deprecated information, or broken screenshots. Even if you update the content, make sure the published date or "last updated" date reflects the refresh. GSC's Performance report can show pages where impressions are declining — these are often freshness-related.
11. Schema markup implementation. Beyond validity (covered in technical checks), audit which schema types you're using and whether you're using all applicable types. A recipe site should have Recipe schema. A local business should have LocalBusiness schema. A blog should have Article and FAQPage schema on relevant posts. Missing schema types are a missed opportunity for rich results and AI search visibility.
12. Open Graph tags. OG tags control how your pages appear when shared on social media. Check for: missing og:title, og:description, og:image. The og:image should be at least 1200x630 pixels. Missing or broken OG images make shared links look unprofessional and reduce click-through from social referrals.
13. Canonical self-referencing. Every indexable page should have a canonical tag pointing to itself. This prevents accidental duplicate content creation via URL variations and is a low-effort best practice. Check that the canonical URL exactly matches the canonical version of the page (with or without trailing slash, with correct subdomain).
14. Duplicate title and meta tags. GSC's Coverage and Performance reports flag duplicate titles. Screaming Frog will list duplicate meta descriptions. These create internal competition where multiple pages signal to Google that they're all about the same thing. Each page should have a unique title and description.
15. Orphan pages. Orphan pages have no internal links pointing to them. They can only be found via sitemap or external links. Google discovers most pages through internal links, so orphan pages are crawled infrequently and rank poorly. Run a crawl, then compare discovered pages against your sitemap. Pages in the sitemap that aren't discovered via crawl are likely orphans. Add internal links to important orphaned pages.

Off-Page SEO Checks (10 Points)

1. Backlink count and growth trend. Pull total referring domains over time from Ahrefs or Semrush. You want to see consistent growth, not a flat line. A sudden spike followed by a drop can indicate a link scheme that's been discounted. A sudden drop in referring domains can indicate manual action or algorithmic devaluation. Note that link count without quality context means little.
2. Referring domain diversity. 100 links from 100 different domains is more valuable than 100 links from 2 domains. Check your ratio of referring domains to total backlinks. A very low ratio (many links from few domains) suggests either a heavy internal linking strategy on a private network or link concentration in a few sources. Both are weaker than genuine diversity.
3. Anchor text distribution. Audit the breakdown: branded vs. naked URL vs. generic vs. partial match vs. exact match. Exact match above 15% is a concern. Very high generic or naked URL percentages are generally fine. Flag any single anchor text phrase that accounts for more than 10% of all links.
4. Toxic links and disavow. Use Ahrefs or Semrush to identify links from obviously spammy sources: link farms, PBNs, hacked sites, irrelevant foreign directories, and sites with no organic traffic of their own. The bar for disavowal should be high — Google ignores most junk links already. Disavow when you see links from clear spam networks that may have been placed intentionally.
5. Branded vs. non-branded traffic ratio. In GSC's Performance report, filter queries to see what percentage of your clicks come from queries containing your brand name. A high branded percentage (70%+) means you're mostly capturing people who already know you, with little organic discovery. Low branded percentage (under 20%) can indicate brand awareness problems. Healthy sites typically see 30-50% branded.
6. Google Business Profile (local businesses). If the site serves a local area, check that GBP is claimed, verified, fully completed, and actively managed. Check review count, average rating, and how recently someone responded to a review. Check that the website URL in GBP points to the correct landing page, not just the homepage.
7. Social signals. Social signals are not direct ranking factors, but they correlate with content that earns links naturally. Check whether your content is being shared on relevant platforms. Low social engagement on content that has been live for months is a signal that it may not be resonating — which explains why it might not be earning links either.
8. Competitor backlink gap analysis. List 3-5 competitor domains in Ahrefs or Semrush and find domains that link to competitors but not to you. These are your highest-priority link building targets — sites in your niche that already link to similar content. The gap analysis tells you where to focus outreach effort.
9. Brand mentions (unlinked). Search Google for your brand name in quotes, then look through results for mentions that don't include a link to your site. These are link building opportunities where you can reach out and ask for a link conversion. The success rate is higher than cold outreach because they already know and are referencing your brand.
10. Content earning links naturally. Which pages on your site have earned the most backlinks? Why? Understanding your natural link magnets helps you create more content with the same characteristics — original data, comprehensive guides, free tools, controversial takes that get cited. If nothing is earning links naturally after 12 months, that's a sign the content isn't differentiated enough to warrant citing.

What to Fix First

A 40-point checklist can be paralyzing without prioritization. Here's the order I use:

Fix immediately (any of these can tank your rankings on their own): HTTPS issues, robots.txt blocking important pages, sitemap containing noindex pages, redirect loops, canonical tags pointing to wrong pages.

Fix within 30 days: Duplicate title tags, missing H1s, internal 404s, Core Web Vitals failures on key page templates, orphan pages that should be ranking.

Fix within 90 days: Content depth gaps on your highest-potential pages, schema markup expansion, anchor text profile if over-optimized, GBP optimization for local sites.

Ongoing: Content freshness, internal linking as new content is published, backlink gap analysis, review and citation management for local.

Run this checklist every 6 months minimum. Site structure, content, and backlink profile all change over time, and new issues appear as you add pages and make changes. The sites with the cleanest SEO profiles are the ones that audit regularly, not the ones that did a comprehensive audit once and never looked again.