Executive summary. Most websites have technical problems that quietly limit how search engines and AI assistants crawl, understand and show their pages. Few of these problems are dramatic; together they waste crawl time, slow pages down and blur what each page is about. This workbook gives marketing teams, founders and developers a structured technical SEO audit they can run themselves in a few days: crawling and access, indexing, site structure and internal links, page experience and speed, on-page signals, and structured data. Each area has checks, what good looks like, where to look and how to prioritise fixes, followed by four worksheets to record findings and track the fix plan.
Why technical SEO still holds most sites back
Technical SEO is the foundation that content and links sit on. Large studies show how common basic problems remain.
Most sites have fixable issues. Ahrefs ran its Site Audit across 1,002,165 domains and counted how many had each issue on at least one page. 72.3% had at least one slow page, 66.2% had pages with only one followed internal link pointing to them, and 59.5% had a page with a missing or empty H1. (Ahrefs, August 2023)
Page experience is improving, but half the web still fails. The 2025 Web Almanac, using Chrome UX Report data from July 2025, found that 48% of mobile websites and 56% of desktop websites had good scores on all three Core Web Vitals. On mobile, Largest Contentful Paint was the weakest metric, with 62% of sites rated good, compared with 77% for INP and 81% for CLS. Home pages did worse than other pages: 45% of mobile home pages passed, against 56% of secondary pages. (HTTP Archive Web Almanac 2025, Performance)
Basic signals are still missing on many pages. The 2025 Web Almanac SEO chapter found canonical tags on 68% of desktop pages and 67% of mobile pages, so roughly a third of pages give search engines no preferred URL. About 85% of sites returned a valid robots.txt file, while around 13% returned a 404 for it. (HTTP Archive Web Almanac 2025, SEO)
Sources: Ahrefs Site Audit study, 1,002,165 domains, 2023 (share of domains with the issue on at least one page); HTTP Archive Web Almanac 2025, Chrome UX Report data, July 2025. Different samples and methods. Visual summary, not Bargaon research.
Not every flagged issue matters equally. A redirect from HTTP to HTTPS is normal; a key service page that is blocked from indexing is a crisis. The value of an audit is not the length of the issue list but knowing which few fixes will change how your most important pages perform.
How the audit works
The workbook follows the path a search engine takes to show a page, from discovering it to understanding it. Work through the four stages in order, because a problem early in the path makes later fixes pointless:
robots.txt, status codes, redirects, sitemaps and internal links that let crawlers find every important page.
Indexing status, canonicals, noindex tags, duplicates and thin pages.
Core Web Vitals, mobile layout, HTTPS and rendering.
Titles, headings, structured data and entity signals for search engines and AI assistants.
Bargaon framework, based on practice. Worksheets for each stage are at the end of this workbook.
You will need Google Search Console, a site crawler (Screaming Frog, Sitebulb, Ahrefs or Semrush site audit), PageSpeed Insights and the Rich Results Test. Our 64-point SEO audit checklist is a shorter companion, and the technical SEO guide explains each concept.