How technical SEO works
The technical issues that cost the most traffic
Technical SEO covers hundreds of possible issues, but only a handful usually matter. These are the ones I find most often, roughly in order of how much damage they do.
Pages that aren’t indexed
If Google hasn’t indexed a page, it can’t rank. Search Console’s Pages report shows which pages are excluded and why. The most damaging causes are a stray noindex tag (often left over from a staging site), pages blocked in robots.txt, canonical tags pointing at the wrong URL, and pages Google considered too thin or too similar to others to bother indexing.
Redirect problems
Redirect chains (A to B to C), redirect loops and old URLs that return 404 instead of redirecting all leak authority. After a redesign, it’s common to find dozens of old URLs with links pointing at them that now go nowhere. Fixing those redirects is often the fastest technical win there is.
Duplicate and thin pages
Tag pages, filtered URLs, printer versions, www and non-www versions, HTTP and HTTPS: there are many ways one page becomes several. Google has to choose between them, and it doesn’t always choose the one you want. Consistent canonical tags, clean internal links and a few redirects usually solve it.
Slow pages
Speed affects rankings at the margins and conversions a lot. Core Web Vitals measure three things: how fast the main content appears (Largest Contentful Paint), how stable the layout is while loading (Cumulative Layout Shift) and how quickly the page responds when someone taps or clicks (Interaction to Next Paint). Failing them on mobile is common, and fixable.
Why speed fixes fail on page-builder sites
Most slow sites I see are built with a page builder and a stack of plugins. The usual response is to install a caching plugin, then an image plugin, then a “speed” plugin, and the score barely moves. That’s because the real problem is the amount of code the page loads before anything appears.
Page builders tend to load their full CSS and JavaScript on every page, whether a page uses those features or not. Add a slider plugin, a popup plugin, analytics, chat and a few fonts, and the browser has a lot of work to do before the visitor sees anything. Caching helps the server, but it doesn’t reduce what the browser has to process.
The fixes that work are structural. Remove plugins you don’t need. Load scripts only on the pages that use them. Serve modern image formats at the right size. Self-host fonts and load fewer weights. Sometimes the honest answer is that the theme can’t be made fast, and a rebuild costs less than another year of patching. If that’s the case, I’ll say so and explain the options for WordPress development or a faster custom build.
A migration checklist that protects your rankings
Whether you’re redesigning, changing platforms or moving domains, these steps keep the traffic you’ve earned:
- Crawl the old site first and export every URL, including ones with backlinks and ones that get organic traffic.
- Map every old URL to the most relevant new one. Avoid redirecting everything to the home page, because Google treats that like a 404.
- Keep URLs the same wherever you can. The safest redirect is the one you don’t need.
- Carry over titles, headings and content on pages that rank well, unless there’s a clear reason to change them.
- Test the new site before launch for
noindextags, blocked resources, broken links and missing redirects. - Launch, then monitor daily for two weeks in Search Console, watching for spikes in 404s and drops in indexed pages.
- Update your sitemap and resubmit it, and update the most important external links if you can.
A migration done this way usually sees little or no traffic loss. Skipping steps 1, 2 and 5 is behind most of the horror stories.
How to read the Search Console Pages report
The Pages report (under Indexing) is the most useful technical SEO tool you already have for free. A quick guide:
- Indexed pages should roughly match the number of pages you want in Google. If it’s much lower, something is blocking indexing. If it’s much higher, you probably have duplicate URLs.
- “Discovered, currently not indexed” means Google knows the page exists but hasn’t crawled it. On a small site this usually points to weak internal linking or low perceived quality.
- “Crawled, currently not indexed” means Google looked and chose not to index it. The page is often thin, duplicated or not useful enough.
- “Excluded by noindex tag” should only list pages you meant to hide.
- “Page with redirect” and “Not found (404)” are normal in small numbers. Look closely if they include pages that used to get traffic.
Technical SEO is the foundation for everything else. Without it, content and link building work harder for less, and even AI SEO depends on pages being crawlable and clearly structured. If you suspect something under the hood is holding your site back, tell me about it below and I’ll send a fixed quote for the audit and the fixes.