A technical SEO audit is a check of a site for errors that prevent search engines from crawling, indexing, and ranking its pages. Unlike a content or link audit, it deals with the “engineering” side: speed, indexing, code, structure, the mobile version. The result is a report with a list of problems sorted by severity and a plan for fixing them.
Key points in 30 seconds
- A technical audit answers the question “why isn’t the site growing even though it has content and links”.
- Core blocks: indexing, crawling, speed (Core Web Vitals), duplicates, mobile version, structure, markup.
- A good report sorts errors by severity (critical / warning / notice) instead of dumping everything in one pile.
- Read the report by priority: first whatever blocks indexing and drags down traffic.
- You can run it yourself with a checklist or order one: the latter is faster and more reliable for complex projects.
What a technical SEO audit is and why you need one
A technical SEO audit is a systematic check of the “engineering” side of a site. It doesn’t assess the quality of texts or count links: its job is to make sure a search bot can crawl the site without obstacles, correctly index the pages you need, and not run into errors that reduce trust in the site.
It differs from a general SEO audit in focus. A general audit covers three areas at once: content, links, and the technical side. A technical audit goes deep into the last one only: server response codes, load speed, duplicates, markup, URL structure. This is often exactly where the reason hides why a site with good content and a promotion budget stays stuck.
An audit is especially needed in five situations: traffic dropped for no obvious reason; the site is moving to a new domain or design; a new project is launching; you’re switching contractors and want an independent picture; or you’re about to invest in links. The last point matters: buying links for a site that isn’t technically ready to receive link equity means throwing the budget away. Foundation first, links second; this logic is covered in detail in our pillar article on link building.
What blocks an audit consists of
| Audit block | What we check | Severity |
| Indexing and crawling | robots.txt, sitemap.xml, noindex, canonical, the Indexing report in GSC | Critical |
| Speed (Core Web Vitals) | LCP, INP, CLS, page weight, caching | High |
| Duplicates and cannibalization | identical content on different URLs, parameters, pagination | High |
| Mobile version | mobile-first indexing, responsiveness, readability | High |
| Structure and internal linking | click depth, orphan pages, link equity distribution | Medium |
| Meta tags | title, description, H1, duplicates and empty values | Medium |
| Schema markup | presence and validity of JSON-LD | Medium |
| Security and response codes | HTTPS, 404/301/302, redirect chains, broken links | High |
No block works in a vacuum: a slow mobile version makes Core Web Vitals losses worse, and duplicates dilute the link equity you build with backlinks. That’s why the report is read as a whole but fixed by priority.
Block 1. Indexing and crawling
This is the foundation: if a page isn’t in the index, nothing else matters. The audit checks the robots.txt file (are important sections blocked), the sitemap.xml (is it up to date, does it contain junk URLs), noindex directives and the canonical attribute, plus the Page indexing report in Google Search Console. A classic mistake: a sitewide indexing block accidentally left in place after development. How to set up the console and read its reports is covered in our article on setting up Google Search Console, and typical causes of problems in the piece on why your site isn’t getting indexed.
Block 2. Speed and Core Web Vitals
Google measures three metrics: LCP (how fast the main content loads), INP (responsiveness to user actions), and CLS (visual stability). Thresholds: LCP ≤ 2.5 s, INP ≤ 200 ms, CLS ≤ 0.1. They’re checked with PageSpeed Insights and the Core Web Vitals report in GSC. A slow site loses rankings primarily in mobile search. What each metric means and how to improve it is covered in our breakdown of Core Web Vitals.
Block 3. Duplicates, canonical, and structure
Duplicates (the same content on different URLs: with parameters, with and without a trailing slash, www and non-www) force Google to choose which version to rank and dilute relevance. Cannibalization is when two of your pages compete for the same query. The audit checks pagination templates, online store filters, and print versions. Structure is assessed by click depth (important pages should be no more than three clicks from the home page) and the presence of orphan pages with no internal links.
Block 4. Meta tags, markup, and security
The final blocks cover details that aren’t critical on their own but together affect click-through rate and trust. Every page should have a unique title and description and a single H1; duplicates and empty values dilute relevance and lower CTR in the SERP. Schema markup (JSON-LD) is run through a validator: correct markup produces rich snippets such as rating stars, breadcrumbs, and prices. The security and response codes block checks that HTTPS works without mixed content, that there are no long redirect chains, and that codes are correct: live pages return 200, deleted ones 404 or 410, moved ones 301 rather than a temporary 302.
How to read the report: a sample excerpt
The value of an audit lies not in the number of errors found but in how the report helps you set priorities. A good report always sorts problems by severity and shows the impact of each. Here’s what an excerpt of such a report looks like:
| Problem | Where | Severity | Impact | What to do |
| 1,240 pages set to noindex | Product pages | Critical | Pages aren’t indexed, traffic is unavailable | Remove noindex, submit for recrawling |
| LCP 4.1 s (threshold ≤ 2.5) | Home page, categories | Important | Losses in mobile search | Optimize images, caching, server |
| 320 duplicate titles | Category pagination | Important | Cannibalization, diluted relevance | Make the template unique, canonical |
| 47 broken internal links | Across the site | Notice | Lost link equity, worse UX | Fix or remove the links |
The reading logic is simple: top to bottom by severity. “Critical” blocks indexing or drags down traffic and gets fixed first. “Important” slows growth and is the second tier. “Notice” means spot improvements for when you get around to them. A report that dumps 400 problems with no priorities is useless: you won’t know where to start.
Technical audit checklist
A short version for a self-check (the full checklist is available as a separate file):
- robots.txt doesn’t block important sections
- sitemap.xml is up to date and has no broken URLs
- no accidental noindex on pages you need
- canonicals are set up correctly
- HTTPS works, no mixed content
- no redirect chains or unnecessary 302s
- broken links (404) found and fixed
- LCP / INP / CLS within thresholds
- the mobile version is responsive and readable
- no duplicate titles or descriptions, one H1 per page
- markup is valid
- structure: no deeper than three clicks, no orphan pages
- pagination and filters don’t generate duplicates
Audit tools
A large share of the checks can be done with free tools: Google Search Console, PageSpeed Insights, a markup validator, crawlers with a free tier. A selection of these tools with instructions is collected in our piece on free SEO tools. Paid crawlers like Screaming Frog or Ahrefs speed up the work on large sites, but for a project with a few hundred pages the free set is enough. That’s exactly why a “free audit” as a marketing promise almost always means a shallow automated report with no prioritization, while the value of an audit lies in manual interpretation.
How much an SEO audit costs
The cost depends on the size of the site and the depth of the check. Market guidelines:
- Express audit (basic errors, a sample of pages): $80–150
- Standard technical audit (mid-sized site, report + work plan): $150–400
- Deep audit of a large project or online store (thousands of URLs, log file analysis): from $400
Prices are approximate and depend on the niche, scope, and competition; we’ll calculate the exact cost for your project. If you need a ready-made report with priorities and a plan rather than a DIY checklist review, you can order a technical SEO audit from our team.
Want to understand what’s holding your site back and get a clear action plan instead of a list of a hundred errors? Order an SEO audit: we’ll send back a report with priorities and a breakdown of every item.
