Technical SEO is the work that lets search engines find, read and trust your pages: whether they can crawl the site, which pages they index, how fast pages load and whether the page structure is clear. It comes before content and links, because a great page that can’t be indexed brings no visitors. This technical SEO checklist covers 25 checks in five groups, each with how to run it using free tools and how to fix it.
You need two free tools for most of these: Google Search Console for your site, and a crawler such as Screaming Frog, which is free for up to 500 URLs.
1. Crawling and indexing
1. Your site is in Search Console. Add and verify the domain property. Without it you are guessing. Fix: verify through your DNS provider.
2. robots.txt doesn’t block important pages. Open yoursite.com/robots.txt. A line that reads Disallow: / blocks everything. Fix: remove the line; block only admin and search result pages.
3. Important pages are indexed. In Search Console, open Pages and check “Why pages aren’t indexed”. Fix: each reason has its own fix; “Crawled, currently not indexed” usually means the page needs more useful content or more internal links.
4. No stray noindex tags. Crawl the site and filter for pages with a noindex meta tag. Staging settings left on after launch are a common cause. Fix: remove noindex from pages that should rank.
5. An XML sitemap exists and is submitted. It should list only pages you want indexed, that return 200 and are not redirected. Fix: generate it from your CMS or build tool and submit it in Search Console.
6. The sitemap is referenced in robots.txt. Add Sitemap: https://yoursite.com/sitemap.xml.
2. Redirects and status codes
7. One version of the site. http, https, www and non-www should all end up at one address with a single redirect. Fix: set it at your host or server.
8. No broken internal links. Crawl the site and filter for 404 responses. Fix: update the link or redirect the missing page.
9. Redirects are permanent. Moved pages should use 301 redirects, not 302. Fix: change them in your server or plugin settings.
10. No redirect chains. A redirect that leads to another redirect slows crawling and loses value. Fix: point each old URL straight at its final address.
11. A useful 404 page. Missing pages should return a real 404 status with links back into the site, not a redirect to the homepage.
3. Page signals
12. Unique titles. Every indexed page needs its own title, around 50 to 60 characters, with the main topic near the front. Fix: the crawler lists duplicates and missing titles.
13. Unique meta descriptions. Not a ranking factor, but they shape the snippet people click. Aim for 120 to 155 characters.
14. One clear H1 per page, matching what the page is about.
15. Canonical tags. Each page should point its canonical tag at itself, unless it is a deliberate duplicate. Fix: check pages with URL parameters and print versions.
16. Images have alt text that describes them. It helps accessibility and image search.
17. Important pages get internal links. Pages linked only from the sitemap rank poorly. Fix: link to key pages from the menu, the homepage and related posts.
4. Structured data
18. Organization data on the homepage: name, logo, address if you serve customers in person, and links to your profiles.
19. Article or BlogPosting data on posts, with author, date published and date modified.
20. BreadcrumbList data on pages below the top level.
21. No errors in Google’s Rich Results Test. Fix: correct missing required fields. Avoid FAQ and HowTo markup expecting rich results; Google no longer shows them for most sites.
5. Speed and mobile
22. Core Web Vitals pass. Check Search Console’s Core Web Vitals report and PageSpeed Insights. Largest Contentful Paint under 2.5 seconds, Interaction to Next Paint under 200 milliseconds, Cumulative Layout Shift under 0.1. Our Core Web Vitals case study shows how we fixed ours.
23. Images are sized and compressed. Serve WebP or AVIF at the size they are shown. Give every image a width and height. Our website speed optimization guide covers the other common causes of slow pages.
24. The site works on a phone. Text readable without zooming, buttons large enough to tap, nothing wider than the screen.
25. HTTPS everywhere, with no pages that load images or scripts over plain http.
The order to work through this technical SEO checklist
- Anything that stops indexing: robots.txt blocks, noindex tags, site-wide redirect problems
- Broken pages and redirect chains on important URLs
- Titles, H1s and canonicals on pages that matter for enquiries
- Speed problems on your most visited pages
- Structured data and the rest
Fix, then check Search Console again after two to four weeks, since changes take time to show.
When a tool is enough, and when you need a person
A crawler and Search Console will find almost everything on this list. You need help when the fixes are in theme code, server settings or a platform you can’t change yourself, or when traffic has dropped and the cause isn’t obvious. That is what our SEO services cover. If you are about to redesign, the website redesign SEO checklist is the place to start.