Technical SEO is the branch of search engine optimization that deals with the technical foundations of a website. The goal is to ensure that search engines can efficiently crawl and index content. This includes factors such as loading speed, mobile optimization, crawlability, URL structure, security, and structured data.
Technical SEO thus forms the foundation for on-page and off-page optimizations and ensures that other SEO measures can fully unfold their effect — without proper technical SEO optimization, a website will not rank well.
In this article, we’ll explain more about technical SEO, list optimization opportunities, and provide a comprehensive technical SEO checklist.
What is Technical SEO?
Technical SEO is extensive and more complex than on-page or off-page SEO, but it is just as important for achieving good rankings.
There are several areas within technical SEO, which we’ll go through together here.
We’ll also provide recommendations and additional tips to help you optimize your website quickly and effectively — step by step.
Crawlability & Indexing of the Website
This is by far the most important part of technical search engine optimization.
In order for a website to appear in search results, search engines must first crawl and then index the website’s pages.
Google uses so-called crawlers (bots) that move through the website to be indexed, store text, images, and other elements, and follow links to discover all pages on the site.
Ultimately, the collected information is stored in Google’s database — the index. Only then will the website appear in search results.
That means: if Google cannot crawl or index a website, it’s impossible to find it.
Therefore, we must ensure that our websites are always crawlable and indexable.
How is that done?
This is possible through a so-called robots.txt file.
First: What is a robots.txt file?
A robots.txt file is a file on a website that gives search engines instructions on which pages they are allowed to crawl and which they are not.
The file must be located in the root directory (i.e. under domain.com/robots.txt) so that search engines can find it.
Creating a robots.txt file is very easy — it can be generated, for example, through an SEO plugin on your website or with online generators.
It’s important that pages which should not appear in search results (e.g. domain.com/admin) are marked with “Disallow:” in the robots.txt file.
Internal Links
As mentioned above, Google discovers all pages of a website through internal links.
If a page has no internal link (a so-called orphan page), Google cannot find, crawl, or index it.
Therefore, it is crucial that all pages that should appear in Google Search are linked within the website.
XML Sitemap
The XML sitemap is a file in .xml format that contains (almost) all URLs of a website.
It also sits in the root directory of the website and allows Google to find pages that are not linked internally or externally.
It also provides several additional benefits — which is why every website should have an XML sitemap.
Mobile-Friendliness
Another key factor in technical SEO is mobile-friendliness.
For several years now, Google has followed the “Mobile-First Indexing” approach.
This means that it’s no longer the desktop version of a page, but the mobile version, that is used for ranking in search results.
If a website is difficult to read or displays incorrectly on mobile devices, it leads to ranking losses — even for users on desktop devices.
The most important aspect here is responsive web design:
The layout must automatically adapt to the screen size of the device.
Text must be readable without zooming, images should scale flexibly, menus must remain easy to use, and more.
Mobile-first is no longer just a buzzword — a website with poor mobile usability will inevitably lose rankings.
PageSpeed & Core Web Vitals
A common stumbling block in technical SEO is the PageSpeed score and Core Web Vitals.
PageSpeed, which can be measured at https://pagespeed.web.dev/, evaluates the loading times of a website.
The Core Web Vitals are UX (user experience) metrics defined by Google that must be met to avoid ranking penalties.
Loading time isn’t just important for technical SEO:
In 2017, Google found that the bounce rate of a website increases by 32% when the loading time rises from 1s to 3s.
Always make sure your website doesn’t load unnecessary scripts, that files are minified, and that the HTML structure is optimized.
Structured Data
Structured data (also called schemas) are snippets of code that provide search engines with additional information about the content of a website. They improve how your site appears in search results, as search engines can display rich snippets (e.g. reviews, recipes, etc.).
There are many different types of structured data available at https://schema.org/.
We recommend using AI or online tools to find and create the right schemas for your website.
With Google Rich Results, you can then check whether Google recognizes and uses the schema in search results.
Important: Structured data doesn’t directly improve rankings, but it significantly increases the click-through rate — which is a positive signal for Google.
Canonical URLs
There are many ways to write a page’s URL, for example:
This flexibility helps users reach the desired site faster, regardless of the URL format they use.
However, it also creates problems:
Google sees these URL variations as different pages and notices that all contain the same content.
This triggers Google’s duplicate content detection.
To prevent this, we use canonical URLs.
A canonical URL is the “correct” version of a page’s URL that Google should prioritize. It’s implemented in the <head> of the page.
This also brings additional benefits for off-page SEO: backlinks are directed to a single URL, which strengthens domain authority.
Always make sure every page has a canonical URL to boost your technical SEO.
SSL Certificate
The difference between http:// (not secure) and https:// (secure) is an SSL certificate.
This certificate, usually provided by your hosting provider, ensures that the connection between browser and website is encrypted and secure.
For technical SEO, a valid SSL/TLS certificate is now mandatory, as Google favors secure websites and marks insecure (http) pages as “not secure.”
Conclusion
Technical SEO includes many different technical aspects of a website that may seem small but have a major impact on performance in search results. To achieve good rankings, you need a solid balance between on-page, off-page, and technical SEO.
If you’re looking for a results-driven and effective SEO agency that can take your SEO performance to the next level, contact us today to schedule a free initial consultation. We look forward to meeting you!
