What a technical SEO audit actually fixes (with real before and after numbers)

Why technical SEO comes first

Most people think of SEO as keywords and content. Those matter, but they sit on top of something less visible: whether Google can actually crawl, read and trust your pages. That's technical SEO.

If the foundations are shaky, great content struggles to rank. Pages without clear headings, missing descriptions, links that bounce through redirects and oversized images all make it harder for Google to understand your site, and harder for visitors to stay on it.

The good news is that technical problems are measurable. Tools like Ahrefs and Semrush crawl every page and flag exactly what's wrong. So rather than talk in general terms, here are real numbers from a recent project.

The before and after

We recently moved a business website from Squarespace to a custom build. Same business, same content, same domain. We audited it with Ahrefs Site Audit before the move and again a few days after launch.

Ahrefs Site Audit, 25 Oct 2026 (before) and 29 Oct 2026 (after).

The before crawl ran on 25 October 2026, on the Squarespace site. The after crawl ran on 29 October 2026, on the new build. A health score of 83 isn't bad, and Squarespace handles some basics well. But 12 errors and 110 warnings meant plenty of small problems were holding the site back.

What we fixed, one by one

Here's what the audit flagged on the old site, and where each one landed after the move.

Missing H1 headings

The H1 is the main heading on a page. Google uses it to work out what the page is about, and screen readers use it to help people navigate. Six pages had no H1 at all. Every page on the new build has exactly one, written to describe what that page offers.

Missing meta descriptions

The meta description is the short snippet that often appears under your page title in Google. When it's missing, Google picks a sentence from the page, which is usually not the one you'd choose. Six pages had none. Now every page has its own, written to earn the click and kept short enough that it doesn't get cut off.

Multiple title tags

Three pages had more than one title tag, which sends mixed signals about which title Google should show. Each page now has one clear title, kept to around 60 characters.

Oversized images

Six images were far larger than they needed to be. Heavy images slow pages down, especially on mobile, and slow pages lose visitors before they've read a word. On the new build, images are compressed, sized for how they're actually shown and loaded as you scroll.

Links pointing to redirects

Forty-two internal links pointed to addresses that redirected somewhere else. Each extra hop wastes a little of Google's crawl time and slows visitors down. Every internal link now points straight to its final page, and every old address redirects once, cleanly, to its new home.

Incomplete social share tags

Sixteen pages were missing some of the tags that control how links look when shared on LinkedIn, Facebook or in messages. Without them, a shared link can appear without a proper title or image. Every page now has a complete set, including a branded share image.

What the score does and doesn't tell you

A health score of 100 means the site has no technical errors holding it back. It doesn't mean the site will rank first for everything overnight. Rankings also depend on your content, your Google Business Profile, reviews, links from other websites and how competitive your industry is.

Think of technical SEO as clearing the road. Once it's clear, the content and local SEO work can actually move you forward. If you're working on those next, our local SEO checklist and free SEO guide are good places to start.

How to check your own site

You don't need paid tools to get a first look:

• Run your homepage through our free website check. It covers Google's speed score and 12 SEO basics in about 30 seconds.
• Search for your business in Google and look at your listing. Is the title clear? Is the description yours, or a random sentence?
• In Google Search Console, check the Pages report for anything that isn't indexed, and why.
• Click through your own menu and footer. Any link that jumps through an old address is worth fixing.

If you're planning a move to a new platform, read our guide to switching platforms without losing your rankings before you start. And you can see this exact before and after on our SEO page.