How to find and fix critical technical SEO errors on your website

Executive overview

Technical SEO is the foundation of search rankings. Unfixed crawl and indexing errors can prevent pages from appearing in search entirely. A site audit tool automates discovery — without one, you rely on manual checks or incomplete Google Search Console alerts.

Fix errors first, then warnings, then notices — in that order.

Understanding error severity levels

• Errors — highest priority; block crawling or indexing directly
• Warnings — lower priority but worth fixing; affect performance and user experience
• Notices — informational; may or may not need action depending on context
• A large error count usually means one root issue repeating across many pages, not hundreds of separate problems

Common errors to fix first

• Incorrect sitemap pages — redirected or 404 pages listed in the sitemap signal to Google that non-existent pages should be indexed; remove them
• Duplicate title tags — identical titles usually mean identical content; investigate whether pages are truly duplicates before adding canonicals or noindex tags
• Pages that can't be crawled — if Google can't access a page, it cannot rank

Warnings worth addressing

• Unminified JavaScript and CSS — slows page load; fixing the root cause once resolves all instances across the site
• Missing alt text on images — not a ranking killer but harms image search visibility; straightforward to fix
• Duplicate meta descriptions — not critical but worth cleaning up

Notices: act selectively

• No-follow attributes on outgoing links — may be intentional (e.g. blog comments); review before changing
• Permanent redirects (301s) — often deliberate; confirm intent before removing
• Links with no anchor text — may be purposeful; only fix if unintended

Prioritising by page, not just issue type

• The audit can surface which individual pages have the most issues — useful for targeting custom or one-off pages that fall outside standard templates
• High-issue pages often share no HTML or formatting with the rest of the site, so fixing global templates won't resolve them

Monitoring progress over time

• Use the compare crawls feature to track fixes and spot new issues introduced by changes
• Watch total errors and warnings trend downward over time; notices can remain stable
• After making a fix, rerun the crawl to confirm — a change can look fixed but introduce new issues