Technical SEO is the process of optimising the technical aspects of a website so that search engines can crawl, index, and rank it effectively. It focuses on how a website is built and functions, rather than the content it contains.
How is technical SEO different from on-page and off-page SEO?
SEO is typically divided into three areas: technical, on-page, and off-page. On-page SEO covers content, metadata, and internal linking. Off-page SEO covers backlinks and external authority signals.
Technical SEO covers the underlying infrastructure: how the site is structured, how fast it loads, and how search engines access and interpret it. All three need to work together. A website with strong content but poor technical foundations will underperform because search engines cannot access or understand it correctly.
What does technical SEO cover?
Technical SEO is a broad discipline. The most common areas include:
Crawlability: whether search engines can access and navigate your pages.
Indexation: whether your pages are being stored and processed by Google.
Site speed and Core Web Vitals: how fast pages load and how stable they are visually.
Mobile-friendliness: whether the site renders correctly on mobile devices.
HTTPS: whether the site uses a secure connection.
Structured data: additional markup that helps Google understand page content.
URL structure, duplicate content, sitemaps, and robots.txt.
What is crawling and indexing, and why does it matter?
Crawling is the process by which Google's bots visit and read the pages on your website. Indexing is what happens next: Google processes and stores those pages in its index, making them eligible to appear in search results. A page that is not crawled or indexed will not rank, regardless of its content quality.
A sitemap helps by listing your pages in a structured format for crawlers to follow. A robots.txt file controls which pages crawlers are allowed to access. Google Search Console shows which pages are indexed and flags any crawl errors, making it the first place to check when investigating indexation issues.
[Screenshot: Google Search Console Coverage report showing the number of indexed pages alongside errors and excluded URLs. Alt text: Google Search Console coverage report showing indexed and excluded pages with error counts.]
How does site speed affect technical SEO?
Site speed is a confirmed Google ranking factor, measured through a set of metrics called Core Web Vitals, which assess loading performance, interactivity, and visual stability. Slow-loading pages affect both rankings and user behaviour: visitors leave faster, and Google treats speed as a signal of overall page quality. In Thailand, where a large share of web traffic comes from mobile devices on variable network connections, page performance is a particularly common issue we flag during technical audits.
Do I need a developer to fix technical SEO issues?
Some technical issues can be resolved without development work, such as updating canonical tags or fixing metadata within a CMS. Others, including server-side rendering problems, redirect chains, or structured data implementation, require developer involvement. At Phoenix Media, we conduct technical audits to identify and prioritise issues, then either implement straightforward fixes directly or prepare a clear brief for the client's development team so that changes are made correctly and do not introduce new problems.
Related KB articles:
• What Are Internal Links and Best Practices for SEO
• The Importance of Website Speed and How to Improve It
• Google Search Console: A Quick Guide
• SEO Plugins: How Important Are They for Ranking a Website
External links:
• Google Search Console Help Centre
• Google's guide to Core Web Vitals