Technical SEO and Core Web Vitals: the base your rankings rest on

Technical SEO is the foundation under your findability. It lets Google crawl, index and understand your website smoothly. Without that base, even strong content and good pages will not rank. In this article you will read what technical SEO exactly involves, what Core Web Vitals are, which mistakes we see most often, and how to check it yourself.

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What is technical SEO?

Technical SEO is everything that ensures search engines can read and display your website without problems. Not the content of your pages, but the foundation beneath it: speed, structure, indexability and code.

You can have the best content in your sector. If Google cannot crawl or understand your pages well, they stay invisible. In practice we see that a large part of lost rankings is not down to the text, but to technical blockages that nobody ever noticed. Also read our short explanation of what technical SEO is for a concise answer.

The pillars of technical SEO

Technical SEO breaks down into a handful of pillars. Below, for each pillar, is what it is, how you check it yourself, and the mistake we come across most often.

Crawlability and indexation

This is the most fundamental layer: can Google find (crawl) your important pages and include them in the search index (index)? What is not in the index simply cannot rank. Search engines start from your robots.txt and follow your links from there.

How to check: type site:yourdomain.com into Google and see whether your important pages come back. In addition, use the indexing report in Google Search Console to see which pages are excluded and why. You will find more depth in our guide on getting a page indexed.

Common mistake: an accidentally leftover noindex tag or a block in robots.txt that was never reverted after a migration.

Site structure and internal links

A logical structure shows Google which pages are important and how they relate. Internal links are the binding agent here: they distribute authority and provide context. A flat, well thought out structure where your key pages are reachable within a few clicks almost always works better than a deep, branching tree.

How to check: click through yourself from your homepage to your most important page. If you need more than three or four clicks, that page sits too deep. Check that every important page gets at least one internal link.

Common mistake: valuable content without a single internal link, also known as an orphan page, which Google therefore barely picks up.

Speed and Core Web Vitals

A fast site is better for your visitors and for your rankings. Google measures the user experience with the Core Web Vitals, which we explain separately below. Speed starts with good hosting and a light page: large images, heavy scripts and slow servers are the usual culprits.

How to check: run your most important pages through a free speed tool or through PageSpeed Insights and check whether you stay under three seconds of load time. For concrete fixes, we have a guide on improving your Core Web Vitals.

Common mistake: testing only on desktop, while the majority of your visitors arrive via mobile on a slower connection.

Mobile friendliness

Google indexes your site based on the mobile version. If something does not work or read smoothly on a smartphone, that counts as the standard experience. Buttons that are too small, text you have to zoom in on and elements that overlap: these are all signals that the mobile experience is off.

How to check: open your site on your own phone and try to carry out the most important action, for example filling in a form. More guidelines are in our guide on building a mobile friendly website.

Common mistake: a beautiful desktop design that loads slowly on mobile or where the call-to-action disappears below the fold.

HTTPS and security

A valid SSL certificate has been a basic requirement for years. It encrypts the traffic between visitor and server, and Google uses HTTPS as a light ranking signal. On top of that, browsers mark sites without a certificate as “not secure”, which costs trust and therefore conversion.

How to check: look for a padlock in the address bar and whether all pages redirect automatically to the https:// version. You can read the background in our explanation of SSL and HTTPS.

Common mistake: a certificate that is installed, but where individual pages or images still load over http (mixed content).

Structured data (schema)

With schema markup you give search engines and AI models extra context about your content: what is a product, a review, an FAQ or a company. Applied correctly, you stand a chance of richer displays in the search results and are more often correctly understood by AI answers.

How to check: test your pages with Google’s Rich Results Test and see whether your schema is recognised without errors.

Common mistake: adding schema for content that is not visible on the page, which goes against the guidelines and can result in a manual action.

Canonicals and duplicate content

If the same or very similar content is reachable via multiple URLs, Google does not know which version to show. Those pages then compete with each other. With a canonical tag you point to the preferred version, so that the ranking signals come together on one URL.

How to check: hunt for the same page at multiple addresses (with and without www, with and without trailing slash, with filter parameters) and check that every variant points to the same canonical. You will find depth at duplicate content.

Common mistake: a canonical that points to the wrong or to a non-indexable page, which knocks you out of the index yourself.

Core Web Vitals explained

Core Web Vitals are the figures with which Google measures the user experience. Three weigh the heaviest, each with a clear target value:

• LCP (loading speed): how fast the largest element on your page appears. Aim for less than 2.5 seconds.
• INP (responsiveness): how fast your page responds to a click or tap. Aim for less than 200 milliseconds.
• CLS (visual stability): whether the page does not jump around while loading. Keep this under 0.1. An overview of the Core Web Vitals lays out those threshold values neatly.

A slow or unstable page drives visitors away. You see that reflected in a higher bounce rate, and Google sees it too. According to research by Pingdom, the bounce rate rises from 6% at a load time of 2 seconds to 38% at 5 seconds. Every extra second therefore literally costs you visitors, and with them leads.

That connection is not an abstraction but measurable. Put load time against bounce rate, and you see how steeply the curve climbs as soon as your page gets slower:

Technical SEO at a glance

This table summarises the pillars: what you check, why it matters, and what you use to check it quickly.

The mistakes we see most often

During an SEO scan we look at the technique first, because the blockage often sits there. The classics:

• pages that load too slowly,
• important pages that are not indexed,
• a structure that is not clear to Google,
• duplicate content that competes with itself,
• broken links and error messages.

Each one of them quietly holds back your rankings, without you noticing.

Technical SEO checklist

Run through this list for your most important pages:

1. Type site:yourdomain.com into Google. Are your important pages in there?
2. Test your load speed with a free speed tool. Under 3 seconds?
3. Do you hit your Core Web Vitals: LCP under 2.5 seconds, INP under 200 milliseconds, CLS under 0.1?
4. Does everything work smoothly on mobile?
5. Does every page have a unique title and description?
6. Do your pages link to each other with internal links?
7. Are there broken links or error pages?

If you want a more extensive version, then use our separate technical SEO checklist.

Technique is the base, not the whole story

Technical SEO is necessary, but not sufficient. A technically perfect site with boring or irrelevant content still does not rank. You need all three: a strong technical base, valuable content and authority.

Want to know whether your technique is in order? Start with a free SEO check. At Gom Nederland, a strong approach, technique included, delivered 400% more daily visitors. Curious what a project costs? Check out our pricing.

Frequently asked questions

Is technical SEO a one-off or ongoing job?

Both. The big base (indexation, speed, HTTPS, structure) you get in order in a single project. After that it is maintenance: with every new page, redesign or migration, technical mistakes can creep back in. That is why we keep an eye on the most important signals in Search Console continuously.

Can I do technical SEO myself?

You can largely carry out the checks in this article yourself with free tools like Google Search Console and PageSpeed Insights. For more complex interventions (canonicalisation, crawl budget, schema, migrations) technical knowledge is needed. Google lays out the official guidelines in Google Search Central.

How fast do I see results from technical SEO?

Fixing indexation problems can become visible within days to weeks, as soon as Google recrawls your pages. Speed and structure work through more gradually. Remember that technique rarely leads to more leads on its own: it takes the brake off, after which strong content and authority make the difference. In the end we steer on leads, not on isolated technical scores.

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