Technical SEO checks whether search engines can access, render and index the pages a business wants customers to find. This checklist covers 15 areas I review during a technical SEO audit. The priorities depend on the site: a broken checkout or accidental noindex needs attention before cosmetic improvements.
This checklist covers the exact issues I look for during a technical SEO audit, organized from the most common to the most damaging. Each item includes what the problem is, why it matters, and how to fix it.
1. Missing or Duplicate Title Tags
Title tags describe a page and are one source Google uses to generate title links. Check missing, duplicate and misleading titles, then compare each title with the page content and the searches it is intended to answer.
Impact: Repeated or inaccurate titles make search results harder to distinguish. Google may generate a different title link from headings or other text.
How to fix: Export a crawl report of page titles. Write concise, descriptive titles for important indexable pages. Preview truncation, but do not treat 60 characters as a Google ranking limit.
2. Slow Page Speed From Unoptimized Images
Oversized images can delay loading, especially when the main image is the Largest Contentful Paint element. Check the actual LCP element in PageSpeed Insights before changing image delivery. A good LCP is 2.5 seconds or less at the 75th percentile of page visits.
Impact: Slow loading can interrupt browsing and purchasing. Measure conversion changes on the affected pages instead of applying a fixed percentage loss to every second of delay.
How to fix: Resize and compress images for their display size. Use an appropriate format, reserve image dimensions and lazy-load images below the fold. Avoid lazy-loading the main LCP image. Test the result rather than converting every asset by rule.
3. Broken Internal Links and 404 Errors
Broken internal links send readers and crawlers to missing pages. Deleted content, changed URLs and typing errors are common causes. A crawl report identifies the destination URL and the pages that still link to it.
Impact: A broken link can stop a visitor reaching a service, product or checkout. Analytics bounce rate alone does not establish why a page ranks or whether Google considers it low quality.
How to fix: Find internal links returning 4xx errors and update their targets. Use a permanent redirect when a removed page has a relevant replacement. Return 404 or 410 when no replacement exists; do not redirect unrelated pages to the homepage.
4. Missing or Incorrect Canonical Tags
Canonical tags identify a preferred URL among duplicate or very similar pages. Google treats canonical annotations as a signal, rather than a command. Inspect unexpected canonical choices before changing tags across a whole template.
Impact: When Google indexes the wrong URL variant, you split ranking signals between multiple versions of the same page. In severe cases, the page you want ranked gets deindexed entirely.
How to fix: Use consistent HTTPS canonical URLs. Paginated pages normally need their own canonical URLs because they contain different items. Consolidate filtered URLs only when their content is duplicate or very similar. See Google pagination guidance.
| Issue | Severity |
|---|---|
| Title tags | Critical |
| Page speed | Critical |
| Broken links | High |
| Canonicals | High |
| Structured data | Medium |
| Alt text | Medium |
| Internal links | Low |
5. No XML Sitemap or Outdated Sitemap
XML sitemaps serve as a direct communication channel to Google about which pages exist on your site and when they were last updated, but I regularly find sites with no sitemap at all, sitemaps containing noindexed or redirected URLs, or sitemaps that have not been updated in months. Google's sitemap documentation is clear that sitemaps help discover new and updated content faster.
Impact: An accurate sitemap helps Google discover URLs. Submission does not guarantee crawling or indexing, and there is no fixed indexing delay for a site without a sitemap.
How to fix: Generate a dynamic XML sitemap that automatically updates when content changes. Remove any noindexed, redirected, or 404 URLs from the sitemap. Submit the sitemap through Google Search Console. Keep sitemap files under 50,000 URLs and 50MB.
6. Missing HTTPS or Mixed Content Warnings
HTTPS has been a confirmed Google ranking signal since 2014, but I still find sites serving mixed content where the page loads over HTTPS while some resources like images, scripts, or stylesheets load over HTTP, triggering browser security warnings that destroy user trust and cause measurable drops in engagement metrics.
Impact: Browsers may upgrade or block insecure resources on an HTTPS page. Check the browser console and test affected images, scripts and forms rather than assuming every mixed resource produces the same warning.
How to fix: Install a valid SSL certificate. Update all internal links and resource references to use HTTPS. Set up a 301 redirect from HTTP to HTTPS. Use the Content-Security-Policy header to block mixed content. Check for mixed content warnings in Chrome DevTools Console.
7. Poor Mobile Usability
Google uses the mobile version of a page for indexing. Compare mobile and desktop content, navigation, metadata and images, and check that important information is available without interactions Google may not perform.
Impact: Missing mobile content can limit what Google indexes. Small text, overlapping controls and horizontal scrolling also make the page harder for customers to use.
How to fix: Test representative pages on a real phone and in browser device emulation. Use PageSpeed Insights and Search Console URL Inspection to investigate rendering and performance. Google retired the Mobile-Friendly Test and the Search Console Mobile Usability report in December 2023.
8. Thin Content Pages With No Search Value
A short page is not automatically low quality. Review whether each page answers a real user need, contains accurate information and adds something beyond repeated boilerplate. Google explicitly rejects a universal word-count target.
Impact: Unhelpful or misleading content can perform poorly in search. Evaluate pages individually and review shared templates for repeated problems; a fixed word-count threshold cannot determine which pages to remove.
How to fix: Audit all indexed pages in Google Search Console. Noindex pages that provide no search value (tag pages, thin archives, placeholder content). Consolidate similar thin pages into fuller resources. Either expand thin pages to provide genuine value or remove them entirely.
9. Missing Structured Data
Structured data describes visible page content in a machine-readable format. Use supported types that fit the page, such as Product markup for product information. Eligibility depends on the feature requirements and does not guarantee a rich result.
Impact: Eligible structured data can change search appearance, but the result and click-through rate are not guaranteed. Google stopped showing FAQ rich results on May 7, 2026, as recorded in its documentation updates.
How to fix: Add accurate Article, Organization or Product data where appropriate. Mark up only content supported by the page and check the relevant Google feature documentation. Use the Rich Results Test for supported Google features and a schema validator for other vocabulary.
Compare before and after using the same pages and reporting window: loading performance, indexing status, organic click-through rate and crawl errors. Record the deployment date so changes can be interpreted in context.
10. Crawl Budget Waste From Parameter URLs
URL parameters can create duplicate or near-duplicate URL combinations. Review server logs and crawl reports to establish whether those combinations consume meaningful crawl activity before introducing restrictions.
Impact: Large sets of unnecessary URLs can complicate discovery and canonical selection. Crawl-budget work is usually a lower priority for small sites than fixing broken or inaccessible pages.
How to fix: Document what each parameter changes. Use consistent internal links and appropriate canonicals for duplicates. Test crawl restrictions carefully: a blocked page cannot expose its canonical or noindex to the crawler.
11. Missing Alt Text on Images
Alt text describes meaningful images for people using assistive technology and helps search engines understand image content. Check missing attributes separately from intentionally empty alt text on decorative images.
Impact: Missing descriptive alt text can leave readers without information conveyed by an image. Alt text is one source of image context, not an absolute prerequisite for every image to appear in Google Images.
How to fix: Describe the information a meaningful image adds in its context. Avoid stuffing keywords into alt text. Decorative images should have empty alt attributes; functional images need text that describes their action.
12. Incorrect Robots.txt Configuration
The robots.txt file controls which parts of your site search engines can crawl, and misconfigured rules can accidentally block important pages, CSS files, or JavaScript resources that Google needs to render and understand your content. I have found sites accidentally blocking their entire /wp-content/ folder, preventing Google from seeing images and styles.
Impact: Blocking resources can prevent correct rendering. A URL blocked in robots.txt can still appear in search if Google discovers it through links. Robots.txt controls crawling, not removal from the index.
How to fix: Read the live robots.txt and check matching rules for important URLs. Review the robots.txt report and URL Inspection in Search Console. To keep a public page out of search, allow crawling of its noindex directive; use authentication for private information.
13. Redirect Chains and Loops
Redirect chains occur when URL A redirects to URL B, which redirects to URL C, forcing both users and search engines through multiple hops before reaching the final destination, and redirect loops occur when redirects create a circular path that never resolves. I find redirect chains of 3+ hops on most sites that have undergone URL structure changes or domain migrations.
Impact: Permanent redirects do not cause a fixed loss of PageRank. Long chains add requests and complicate crawling; loops prevent a destination from loading. Google recommends direct redirects to the final destination.
How to fix: Crawl your site with Screaming Frog and filter the redirect report for chains and loops. Update all redirects to point directly to the final destination URL in a single hop. Update internal links to point directly to the final URL rather than relying on redirects.
14. Missing or Poorly Implemented Hreflang Tags
For sites targeting multiple languages or regions, hreflang tags tell Google which version of a page to serve to users in each locale, but implementation errors are extremely common and cause Google to serve the wrong language version to searchers, resulting in high bounce rates and lost conversions in international markets.
Impact: Incorrect language annotations can make it harder to show the intended regional version. Translation alone does not make pages duplicates; investigate canonical and indexing decisions separately.
How to fix: Link each language or regional version to itself and the other versions, with reciprocal annotations. Use x-default for an appropriate fallback or selector page when needed; it is optional. See Google hreflang guidance.
15. No Internal Linking Strategy
Internal links distribute authority throughout your site and help Google understand topic relationships between pages, but most sites I audit have no deliberate internal linking strategy, resulting in "orphan" pages with zero internal links and important pages buried 4+ clicks from the homepage. The sites that rank best in competitive niches consistently have well-structured internal linking that guides both crawlers and users through logical content paths.
Impact: Internal links help people and crawlers discover related pages. Link count and click depth alone do not guarantee rankings; relevance and the purpose of each destination matter.
How to fix: Make important pages reachable through relevant navigation and contextual links. Use descriptive anchor text and inspect orphan pages before adding links. There is no universal minimum number of internal links per page.
How to Prioritize Your Technical SEO Fixes
Not all 15 issues carry equal weight. When I deliver a technical SEO audit to a client, I prioritize fixes based on a combination of impact and implementation difficulty. Here is how I rank the urgency.
| Priority | Issues | Typical Fix Time |
|---|---|---|
| Critical (fix this week) | Robots.txt blocking content, redirect loops, missing HTTPS | 1-2 days |
| High (fix within 2 weeks) | Title tags, broken links, canonicals, page speed | 3-5 days |
| Medium (fix within 1 month) | Structured data, sitemap, mobile usability, alt text | 1-2 weeks |
| Ongoing | Thin content, internal linking, crawl budget, hreflang | Continuous |
Quick Audit Checklist
- Titles descriptive and appropriate to each page
- Images in WebP with alt text
- Zero broken internal links
- Self-referencing canonicals set
- XML sitemap submitted and clean
- HTTPS with no mixed content
- Mobile usability passing
- Structured data validated
- Redirects point directly to relevant final URLs
- Internal linking strategy in place
Tools I Use for Technical SEO Audits
A thorough technical audit requires multiple tools because no single tool catches everything. These are the tools I use on every audit, and each serves a specific purpose in the diagnostic process.
Screaming Frog SEO Spider: The foundation of every technical audit. Crawls your entire site and identifies broken links, redirect chains, missing titles, duplicate content, and dozens of other issues in a single pass.
Google Search Console: Review indexing, URL Inspection, Core Web Vitals and search performance. Search Console reports describe Google Search data; compare them with analytics and server logs when investigating a change.
PageSpeed Insights: Compare available real-user field data with a reproducible lab test. Field data describes observed visits; the lab test helps identify possible causes. A Lighthouse score is not a Google ranking score.
Ahrefs Site Audit: Catches issues that Screaming Frog misses, particularly around content quality, internal link distribution, and keyword cannibalization.
If you are a small business owner without access to these tools, start with Google Search Console. It is free and provides the most critical data about how Google interacts with your site.
Why Technical SEO Matters More in the Age of AI Search
Google AI search features depend on accessible, eligible web content. Begin with crawling, indexing and useful information, then measure visibility for a defined query set. Technical checks are also part of diagnosing stalled SEO results.
For Google AI Overviews and AI Mode, pages must be indexed and eligible to appear with a snippet. Special AI markup is not required. Meeting the requirements does not guarantee selection as a source. See Google AI feature requirements.
Review access and indexing before attributing missing AI citations to content formatting.
Frequently Asked Questions
How often should I run a technical SEO audit?
I recommend a comprehensive technical SEO audit at least once per quarter, with automated monitoring through Google Search Console running continuously. Major site changes like redesigns, CMS migrations, or significant content additions should trigger an immediate audit. Most of the 15 issues on this checklist can reappear after routine site updates, so quarterly checks catch problems before they cause measurable traffic loss.
Can I do a technical SEO audit myself, or do I need to hire a professional?
Free tools can identify many issues, but prioritization needs context about the site and its business. Start with Search Console and a bounded crawl. Use specialist help when a change affects important revenue pages or requires deployment experience.
How long does it take to see results after fixing technical SEO issues?
A fix must be crawled and processed before its search effect can be assessed. Timing varies by URL, problem and crawl frequency. Verify the technical correction immediately, then monitor indexing and query-level performance without promising a fixed recovery date.
Is technical SEO more important than content or backlinks?
Fix access or indexing failures that prevent important content being considered. After that, prioritize technical work, content and promotion by the evidence for the affected pages. No single category deserves priority in every case.