Technical SEO: What It Is and Why It Matters

Technical SEO is the foundation your rankings are built on. You can write the best content on the internet, but if Google can't crawl it, render it, or understand it, nobody will ever see it.

The good news: technical SEO isn't as complicated as it sounds. Most of it boils down to "make your site easy for search engines to read." Here's everything you need to know.

What Technical SEO Actually Means

SEO has three main buckets:

• On-page SEO — Your content, keywords, headings, meta tags
• Off-page SEO — Backlinks, brand mentions, social signals
• Technical SEO — Everything about your site's infrastructure that affects how search engines crawl and index it

Technical SEO is the plumbing. Nobody sees it, but when it breaks, everything stops working.

Crawling: Can Google Find Your Pages?

Google discovers pages by following links. It starts with known pages, finds links on those pages, follows them, and repeats. This is crawling.

Things that block crawling:

• robots.txt rules — This file tells crawlers what they can and can't access. A single misplaced line can hide your entire site. Check yours at yoursite.com/robots.txt.
• Orphan pages — Pages with no internal links pointing to them. If no page links to it, crawlers can't find it (unless it's in your sitemap).
• JavaScript rendering issues — If your content is loaded entirely by JavaScript, Google might not see it. Google does render JavaScript, but it's slower and less reliable than plain HTML.
• Crawl budget waste — Every site gets a finite crawl budget. If Google spends it crawling useless pages (faceted navigation, session IDs, infinite scroll), your important pages get crawled less often.

Indexing: Does Google Store Your Pages?

Crawling and indexing are different things. Google can crawl a page but decide not to index it. "Crawled — currently not indexed" is one of the most common issues in Google Search Console.

How to check what's indexed:

• Search site:yoursite.com in Google to see all indexed pages
• Check the "Pages" report in Google Search Console for detailed status
• Use the URL Inspection tool to check specific pages

Common reasons pages don't get indexed:

• Thin content — Not enough value to warrant indexing
• Duplicate content — Google picks one version and ignores the rest
• noindex tag — You (or your CMS) told Google not to index it
• Low authority — New sites with few backlinks struggle to get pages indexed quickly

XML Sitemaps

A sitemap is a file that lists every page you want Google to index. It's like handing Google a map of your site instead of making it wander around.

Best practices:

• Include only indexable pages (no 404s, no redirects, no noindex pages)
• Keep it under 50,000 URLs per sitemap file
• Include lastmod dates so Google knows when content changed
• Submit it in Google Search Console
• Reference it in your robots.txt: Sitemap: https://yoursite.com/sitemap.xml

Site Speed and Core Web Vitals

Google measures three Core Web Vitals:

• LCP (Largest Contentful Paint) — How fast the main content loads. Target: under 2.5 seconds.
• INP (Interaction to Next Paint) — How fast your site responds to user interactions. Target: under 200ms. (This replaced FID in March 2024.)
• CLS (Cumulative Layout Shift) — How much the page layout jumps around while loading. Target: under 0.1.

These are real ranking factors. Not theoretical — Google confirmed it. Sites with good Core Web Vitals rank better than identical sites with poor vitals.

Check yours at pagespeed.web.dev or in Google Search Console under "Core Web Vitals." For detailed fixes, see our page speed guide.

HTTPS and Security

HTTPS has been a ranking signal since 2014. If your site is still on HTTP, you're at a disadvantage.

Beyond rankings, browsers now show "Not Secure" warnings for HTTP sites. That kills trust and conversion rates.

What to check:

• Your SSL certificate is valid and not expired
• HTTP URLs redirect to HTTPS (301 redirect)
• No mixed content (HTTPS page loading HTTP resources)
• Your sitemap and canonical tags use HTTPS URLs

Mobile-First Indexing

Google switched to mobile-first indexing in 2023. This means Google primarily uses the mobile version of your site for indexing and ranking.

If your desktop site has content that your mobile site doesn't, Google might not see that content. This catches a lot of people off guard.

Check for:

• Same content on mobile and desktop
• Same structured data on both versions
• Same meta tags on both versions
• Images and videos accessible on mobile

Canonical Tags

Canonical tags tell Google "this is the main version of this page." They're essential when you have multiple URLs that show the same or similar content.

Common scenarios where you need canonicals:

• URL parameters: yoursite.com/shoes vs yoursite.com/shoes?color=red
• www vs non-www: www.yoursite.com vs yoursite.com
• HTTP vs HTTPS versions
• Pagination: page 1 of category listings
• AMP pages pointing back to the original

Every page should have a self-referencing canonical tag at minimum. This is one of the things AuditMySite checks automatically.

Structured Data (Schema Markup)

Structured data is code that tells Google exactly what your content represents. It's like labeling boxes instead of making Google guess what's inside.

Benefits:

• Rich results in search (stars, FAQs, prices, events)
• Better understanding of your content
• Potential for featured snippets and knowledge panels

Start with the basics: Organization on your homepage, Article on blog posts, Product on product pages, LocalBusiness if you have a physical location.

URL Structure

Clean URLs help both users and search engines. Compare:

• Good: yoursite.com/blog/technical-seo-guide
• Bad: yoursite.com/index.php?id=4827&cat=3&lang=en

URL best practices:

• Use hyphens, not underscores
• Keep URLs short and descriptive
• Include target keywords when natural
• Use lowercase only
• Avoid unnecessary parameters and session IDs

International SEO (hreflang)

If your site targets multiple languages or regions, you need hreflang tags. They tell Google which version of a page to show users in different locations.

Without hreflang, Google might show your French page to English speakers, or your US page to Australian users when you have an AU-specific version.

This is an advanced topic, but if you operate in multiple countries, it's important. Get it wrong and you can cannibalize your own rankings.

How to Audit Your Technical SEO

You have two options:

1. Manual audit — Work through our SEO audit checklist item by item. Thorough but time-consuming.
2. Automated scan — Run your URL through AuditMySite and get a report covering most of these issues in 30 seconds. Then focus your manual effort on the items that need human judgment.

Either way, technical SEO isn't a one-time project. Sites change. New pages get added. Plugins get updated. Servers get reconfigured. Run audits regularly — monthly at minimum — to catch issues before they hurt your rankings.