A page can only rank if Google is allowed to index it, and if the right URL is marked as the master copy. Indexability bugs are the most damaging in SEO because they make good content invisible. Here's what we check and why.
You can have the best content and the strongest links in your niche, but if a page carries a stray noindex or canonicalises to the wrong URL, it will never rank. This is the highest-leverage category in any audit.
Indexability is binary at the gate: a page is either eligible to appear in search or it isn't. The cruel part is that these failures are silent. The page loads perfectly for you, ranks nowhere, and there is no error message, just a quiet absence from the results. A single line in a shared template or one misconfigured canonical can remove an entire section from search, and because traffic data lags crawling by days, the drop often isn't noticed until well after the change that caused it.
A page is indexable only when four conditions all hold at once. Miss any one and the page won't appear in search, no matter how good it is.
No noindex meta tag and no X-Robots-Tag: noindex header on the page.
Not blocked in robots.txt, so Google can actually fetch and read the page.
A canonical that points to itself (or no conflicting canonical sending Google elsewhere).
A successful HTTP 200 status, not a 3XX redirect, a 4XX, or a 5XX error.
The two checks that deindex more pages than anything else.
How rel=canonical works, the canonical mistakes that quietly deindex pages (pointing to a redirect, a 404, or every page to page 1), and how to keep canonical, hreflang and internal links aligned.
When noindex is the right tool, when it silently kills rankings, and how a stray noindex on a shared template can deindex an entire section without anyone noticing.
Grounded in the real checks the crawler runs on every page.
A page is indexable when search engines are both able and allowed to add it to their index. Those are two separate permissions, and a page needs four conditions to hold at once to satisfy them: no noindex meta tag or X-Robots-Tag header, no robots.txt rule blocking crawling, a self-referencing canonical or at least no conflicting one, and a 200 status.
Fail any single one of those and the page will not appear in results, regardless of how good the content is. That is what makes indexability the highest-leverage category in an audit: it is a gate, not a scale.
The usual causes are a short list. A stray noindex shipped on a shared template, a canonical pointing to the wrong URL (a redirect, an error page, or every paginated page to page 1), a robots.txt rule that blocks crawling, or pages that started returning 4XX or 5XX responses after a migration.
All four share the same shape: they ship silently, and the traffic loss arrives days later once Google has re-crawled and honoured the change. An audit that flags pages which became non-indexable since the last crawl catches them on the day they ship, which is the difference between a five-minute rollback and a fortnight of lost rankings.
Not every excluded page is a mistake. Thank-you pages, internal search results and thin filter pages should all stay out of the index, and seeing them listed as excluded is a sign the setup is working.
The problem is only when a page you want ranking is non-indexable. Search Console's Pages report separates intentional exclusions from accidental ones, and the Kalenux audit deliberately flags only the indexable pages that should not be missing, so the signal is not buried under pages you never wanted in search.
To remove a page from the index, use noindex and allow crawling. Do not reach for robots.txt: blocking crawling stops Google seeing the noindex directive, so the URL can remain indexed, typically showing up without a description.
The clean division is that robots.txt manages crawling and noindex manages indexing. They are not interchangeable, and combining them on the same URL actively defeats the purpose. See the robots.txt guide for the full explanation.
Free to start. Catch stray noindex tags and broken canonicals before they cost you rankings.
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