Website Errors and the Types of SEO Audits

13 June 2026 · By John Carlsson

The most common website errors are broken links, duplicate content, missing or duplicate titles and descriptions, slow pages, redirect chains, crawl errors and poor mobile layouts. The four main types of SEO audit are technical, on-page, off-page (links) and content audits, and each one finds a different group of these problems.

Common website errors include broken links, duplicate content, missing meta tags, slow loading speeds, incorrect redirect chains, crawl errors, and poor mobile responsiveness. There are several types of SEO audits: technical audits (server performance, indexability, site architecture), on-page audits (content quality and keyword optimisation), off-page audits (backlink profile), and content audits (thin or outdated pages).

The most common website errors and their impact on SEO

Before looking at the types of SEO audits, it helps to know the errors they uncover. Broken internal links (linking to pages on your own site that no longer exist) waste the authority passed through those links and create a poor experience for visitors who click them.

Duplicate content (the same or very similar content appearing at multiple URLs) confuses search engines about which version to show and can dilute ranking signals across multiple pages. Missing or duplicate meta tags reduce how well your pages represent themselves in search results. Slow loading pages lead to higher bounce rates and, since 2021, directly affect Core Web Vitals scores used as a ranking signal. Incorrect redirects, particularly chains of multiple hops, lose a portion of the authority they're intended to pass.

Understanding the four types of SEO audits

A technical SEO audit specifically investigates infrastructure: how the site is built, served, and accessed by crawlers. An on-page audit investigates what's on the pages: content, structure, and metadata. An off-page audit investigates what's happening outside your site: backlinks, brand mentions, and the reputation your site has earned across the web. A content audit specifically assesses the quality and current relevance of your pages, identifying which are thin, outdated, or targeting topics too vague to rank for. Most comprehensive SEO projects run all four, though they can be prioritised differently depending on the site's specific situation.

Which type to run first

For most sites that haven't been audited before, starting with a technical audit makes the most sense — it establishes whether the site can be found and accessed at all before investing effort in improving what's on those pages. Once technical issues are addressed, an on-page audit identifies content and metadata improvements. For sites that are already technically healthy but struggling with visibility, a content audit to identify thin or misaligned pages, or an off-page audit to understand the backlink gap vs competitors, is more valuable than running another technical check on an already-clean site.

Key Takeaways

Common errors: broken links, duplicate content, missing tags, slow speeds, bad redirects.
Four audit types cover technical, on-page, off-page, and content dimensions.
Start with a technical audit if you've never audited before — it's the foundation everything else builds on.

Frequently asked questions

Which website errors hurt SEO the most?

Broken internal links waste the authority passed through them and frustrate visitors who click them. Duplicate content, where the same or very similar content appears at several URLs, confuses search engines about which version to show and can dilute ranking signals. Missing or duplicate meta tags weaken how pages present themselves in search results. Slow pages lead to higher bounce rates and, since 2021, directly affect the Core Web Vitals scores used as a ranking signal. Incorrect redirects, especially chains with several hops, lose part of the authority they are meant to pass on.

What are the four types of SEO audits?

A technical SEO audit investigates infrastructure: how the site is built, served and accessed by crawlers. An on-page audit looks at what is on the pages, including content, structure and metadata. An off-page audit examines what happens outside your site, such as backlinks, brand mentions and the reputation your site has earned across the web. A content audit assesses the quality and current relevance of pages, finding those that are thin, outdated or targeting topics too vague to rank for. Most comprehensive SEO projects run all four, prioritised to suit the site.

Which type of SEO audit should I run first?

For most sites that have never been audited, a technical audit is the best starting point. It establishes whether the site can be found and accessed at all before you invest effort improving what is on the pages. Once technical problems are fixed, an on-page audit identifies content and metadata improvements. For sites that are already technically healthy but still struggling for visibility, a content audit to find thin or misaligned pages, or an off-page audit to understand the backlink gap with competitors, is more valuable than repeating a technical check.