Technical SEO: the foundation of getting found

You can have the most beautiful website and the best copy, but if Google can't read your pages properly, it won't do you much good. That is what technical SEO is about: everything under the hood that decides whether search engines can find and understand your site, and how fast that site loads for a visitor. This article covers what falls under it and what you can have checked without any technical knowledge.

What is technical SEO?

Technical SEO is everything that makes sure search engines can find and read your website. Your copy and the links pointing to your site from outside are not part of it. It is about the foundation underneath: how fast your pages load, whether Google can reach them properly, whether your site works well on a phone and whether the code explains clearly what a page is about.

SEO breaks down roughly into four parts: on-page SEO (your copy and page structure), off-page SEO (links and authority from outside), local SEO (getting found in your own region) and technical SEO. This article is about that last one and about why it sits under the other three. The whole picture is in what SEO actually is.

Technical SEO covers crawling and indexing, loading speed, mobile friendliness, security with HTTPS, structured data and the internal link structure. That sounds technical, but you don't have to build it yourself to understand what's going on and what you can have checked.

Why the technical side is the base of all your SEO

First Google has to be able to read your pages

Say you have strong copy and a few good backlinks, but a technical error keeps Google away from half your pages. Then those pages simply don't exist for the search engine, and all the work on copy and links brings in nothing there. That is why good SEO starts with the technical side.

A slow site costs visitors and rankings

Speed counts in how Google ranks pages, and your visitor notices it just as much: on a slow page, people leave before they've seen anything.

Work it back to your revenue. The number of customers from your website is roughly your number of visitors times your conversion rate, the percentage that get in touch or buy. Speed pulls on both at once, so work on your load time is also work on your inquiries.

Crawling and indexing: how Google reads your site

Before a page can rank, Google has to do two things with it: fetch your site and walk through the pages (crawling), and decide which pages end up in the search engine (indexing). If something goes wrong in either step, you won't see your page show up, however good it is.

Crawlability: can Google reach your pages?

Google sends a small program around that combs through your site and hops from link to link. If it can get everywhere, your site is easy to crawl. You arrange that with a logical internal link structure, a sitemap (a list of all your pages that you submit to Google) and a robots file that says where the search engine may and may not go. If you lock the wrong thing by accident, you shut pages out without noticing.

Indexing: do your pages get into the search engine?

Being found is not the same as being included. After crawling, Google decides whether a page is worth keeping. A canonical tells Google, for near-identical pages, which version is the real one, so you don't compete with yourself. A noindex says the opposite: this page should stay out of the search engine. That is handy for a thank-you page, less handy when it sits on your most important page by accident.

On existing sites, the gains are usually in this kind of mistake: pages that are set to noindex unintentionally, duplicate addresses that get in each other's way and important pages that aren't linked from anywhere. You only notice them when you see that a page you're proud of simply isn't in Google.

Speed and Core Web Vitals

Speed has been a ranking factor for years, and Google now measures it very concretely with a set of metrics called Core Web Vitals. It comes down to three things you also feel yourself when a site doesn't run well.

What Google measures exactly when it comes to speed

The first is how quickly the largest part of your screen appears: the photo or heading your eye goes to. The second is how fast the page responds when you tap or type something, so whether it does what you ask right away or hesitates first. The third is whether everything stays in place while the page loads, or whether it all still jumps around just as you're about to tap. Each of those three can cost you visitors.

What makes your site faster

The biggest culprits are usually the same: images that are too heavy, a pile of scripts and plugins that load on every page, and slow hosting. Compressing images and throwing out unnecessary code often makes a big difference on its own, and scripts that aren't needed right away can be loaded later. How much difference it makes varies per site.

Mobile: why your site has to work on a phone

Google judges your site on its mobile version by default. That is called mobile-first indexing: what you see on your phone is what counts for your position. For a small-business site that means: readable text without zooming in, buttons you can hit with a thumb, and the same content as on desktop. A large share of your visitors arrives on a phone anyway, so that small screen is also where you make your first impression.

Structured data: explaining your site to Google and AI

Structured data (also called schema) is a piece of code that explains, in a fixed language, what is on your page. It sits invisibly in your page and tells the search engine: this is a business, this is an address, this is a review. That way Google doesn't have to work out from your text what an address or a review is.

That is getting more important now that your site can also show up in AI search engines like ChatGPT and Perplexity, and in the AI summaries above Google's search results. Those tools have to understand what you do: the clearer your site explains itself, the better your chance of being mentioned. You can read more about this in the future of SEO is GEO.

Internal links: how your pages strengthen each other

Internal links are the links from your own pages to your other own pages. They do two things at once: they show the search engine the way to every page, and they pass on authority. A strong page that links to another gives that page part of its strength.

A logical structure therefore helps your findability and your visitor, who clicks through more easily. Link pages that belong together to each other, so that Google sees you really know something about a subject. I work that approach out in content clusters and topical authority.

Why a site on Next.js gets much of this right by default

What Next.js brings by default

A lot of technical SEO doesn't need repairing afterwards if the foundation is already good. A site built on a modern base like Next.js does much of this well on its own: fast load times, pages Google can read right away, mobile as the starting point and clean code without a stack of plugins getting in each other's way.

Repair it or rebuild it?

With a site that is slow and messily built, you often keep bailing water with the faucet running: every fix exposes a new problem. That is called technical debt, overdue maintenance that piles up. In that case, rebuilding on a good foundation is often wiser than patching forever, and in the long run it can also work out cheaper.

Rebuilding is a website job. The ongoing side is Vizibly System, my SEO service: it measures how your site performs technically, and every month I improve whatever is falling behind.

What you can check yourself

You don't have to be a developer to see whether your technical setup is in order. These are the questions that give you a first picture:

• Are your most important pages really in Google? Search for site:yourdomain.com and see whether they are all there.
• Does your site load fast on a phone, even without wifi? A slow load time costs you visitors, and speed counts toward your position.
• Does the mobile version work and look as good as the desktop version?
• Is there an accidental noindex or block on a page that should be found?
• Can you get to every important page from your homepage in a few clicks?

Want a first measurement right away? With the free SEO checker you see in a few seconds how your site is doing technically. Those questions and that checker work on any system, whether your site runs on WordPress, Shopify or custom code.

Frequently asked questions about technical SEO

What is technical SEO?

Technical SEO is all the technical work that decides whether search engines can find, read and understand your website: crawling and indexing, loading speed, mobile friendliness, security with HTTPS, structured data and internal links. Without that base, your copy and backlinks don't come into their own.

What are the 4 types of SEO?

On-page SEO (your copy and page structure), off-page SEO (links and authority from outside), local SEO (getting found in your own region) and technical SEO (the foundation under the rest). They work together: strong in one area and weak in another rarely gets you a top position.

What is a technical SEO specialist?

Someone who focuses on the technical side of findability: tracking down crawl errors, improving load time, getting indexing in order, adding structured data and guarding the site structure. With Vizibly that isn't a separate role: I handle the technical side together with your copy and links, so that nothing falls between two specialists.

Do you build new websites too?

Yes, building websites is my other service, next to SEO. With a site that has a lot of overdue maintenance, rebuilding on a modern base is sometimes more effective than continuing to repair. If every fix exposes a new problem, a new site is worth considering.