What Does "Alternate Page With Proper Canonical Tag" Mean?

What "Alternate page with proper canonical tag" means

The status sits in the "Not indexed" group of the Page indexing report. Google's description is three sentences: the page is marked as an alternate of another page; it correctly points to the canonical page, which is indexed, so there is nothing you need to do; and alternate language pages are not detected by Search Console. ^{[1]Google Search Console Help. Page indexing report} The examples Google gives for an alternate are an AMP page with a desktop canonical, a mobile version of a desktop canonical, or the desktop version of a mobile canonical. ^{[1]Google Search Console Help. Page indexing report}

The URL Inspection tool describes the same situation from the page's side. A page that is one of a set of alternate pages should declare its canonical explicitly, while a page that is not an alternate can leave the "User-declared canonical" field at "None". ^{[4]Google Search Console Help. URL Inspection tool} Inspecting a URL in this status returns the verdict "URL is an alternate version", and the indexed URL appears as the Google-selected canonical. ^{[4]Google Search Console Help. URL Inspection tool} Read together, the two help pages cover more than AMP and mobile pairs: a filtered, sorted or tracking variant that carries a rel="canonical" link to the clean URL is an alternate pointing at an indexed canonical, and it is reported here as well.

Behind the label is canonicalization, Google's process of selecting the representative URL for a piece of content. When Google finds multiple pages whose primary content is the same or very similar, it clusters them and marks the one it judges most complete and useful for search users as the canonical. ^{[2]Google Search Central. What is canonicalization} With this status, your rel="canonical" link did its job. Google ranks it as a strong signal that the specified URL should become canonical, second only to a redirect, while sitemap inclusion is a weak one. ^{[3]Google Search Central. How to specify a canonical URL with rel="canonical" and other methods}

When to fix it and when to leave it

Google's own guidance has no fix step. Duplicate or alternate pages should not be indexed, and having a page marked duplicate or alternate is usually a good thing, because it means Google found the canonical page and indexed it. ^{[1]Google Search Console Help. Page indexing report} Its usage guide adds that non-indexed URLs can be fine. ^{[1]Google Search Console Help. Page indexing report}

The last row is the one that costs traffic. This status means Google folded the variant into the canonical; cannibalization means two pages too different to fold are both indexed and trading positions for the same query. The Keyword Cannibalization Checker reads Search Console data and lists the page pairs that compete on the same queries, with a merge, canonical, de-optimize or differentiate recommendation for each; merge or redirect competing pages explains how to choose between them.

Example: one product page, five URLs

The table below is constructed to illustrate the pattern. Each row is a URL as it appears in the Page indexing report and URL Inspection, with 28 days of clicks from the Performance report.

Rows two and three are the status working as intended. The variants declare the clean product URL as canonical, Google accepted it, and nothing needs doing. Their zero clicks are not a loss: click, impression and position data for all variations of a page are assigned to the canonical URL Google selects, so the 860 clicks on row one already include visits that landed on the variants. ^{[5]Google Search Console Help. What are impressions, position, and clicks?}

Row four is the hidden problem. The women's cut is a separate product with its own search demand, but the product template wrote the men's URL into its canonical tag. The status is correct from Google's side, but the women's page cannot appear in Search while the tag stays. That is the second row of the decision table, and no report flags it as an error.

Row five is the opposite case. The review page shares most of its text with the product page, but Google did not fold it, so both are indexed and both can show for "rain shell". It is not a Page indexing problem; it shows up in the Performance report as two pages splitting impressions for one query, as in the cannibalization examples post. A keyword map with one URL per query keeps row five from being written in the first place.

How to check it

1. Open the Page indexing report, click "Alternate page with proper canonical tag" in the "Why pages aren't indexed" table, and read the examples. The list is limited to 1,000 rows and does not necessarily show every affected URL. ^{[1]Google Search Console Help. Page indexing report}
2. Inspect each URL that matters with the URL Inspection tool. "User-declared canonical" shows what the page declares; "Google-selected canonical" shows the page Google chose as authoritative when it found similar pages on your site. ^{[4]Google Search Console Help. URL Inspection tool} For this status the two match. The Google-selected value can be a few hours out of date from the index. ^{[4]Google Search Console Help. URL Inspection tool}
3. Ask whether the Google-selected canonical is the page you want ranking. If it is, stop.
4. If it is not, change the <link rel="canonical"> in the page's <head> to point at the page itself, using an absolute URL, and do not use robots.txt or noindex to steer the choice. ^{[3]Google Search Central. How to specify a canonical URL with rel="canonical" and other methods} Then request indexing for the page. A request does not guarantee indexing, and the live test cannot predict whether a URL will be treated as canonical. ^{[4]Google Search Console Help. URL Inspection tool}
5. Re-inspect after the next crawl. If Google still selects the other URL although the tag now points at the page itself, see why Google chooses different canonical URLs. The five fixes for near-duplicate pages are in how to fix keyword cannibalization.

The thing people get wrong

Hundreds of URLs under "Not indexed" look like hundreds of problems, so every alternate gets a redirect or a noindex tag. Google says the opposite: having a page marked duplicate or alternate is usually a good thing, because the canonical was found and indexed. ^{[1]Google Search Console Help. Page indexing report} And noindex is the wrong tool for canonical selection within one site, because it blocks the page from Search completely; Google names rel="canonical" annotations as the preferred solution. ^{[3]Google Search Central. How to specify a canonical URL with rel="canonical" and other methods}

The mirror mistake is reading the alternate's empty Performance row as lost rankings. Nothing was lost; the data is credited to the canonical URL. ^{[5]Google Search Console Help. What are impressions, position, and clicks?} Watch the canonical's own average position and CTR, not the alternate's zeros.

Alternate page with proper canonical tag vs the other canonical statuses

Google's note on the second status is that it is not an error but working as intended, because Google does not serve duplicate pages. ^{[1]Google Search Console Help. Page indexing report} Its note on the third is that a declared canonical which is not similar to the page will never be chosen. ^{[1]Google Search Console Help. Page indexing report}

Where the report can mislead

The example list is capped at 1,000 rows and is not guaranteed to show every URL in the status. ^{[1]Google Search Console Help. Page indexing report} Alternate language pages are not detected by this status, so hreflang variants are missing from it, even though Google prefers URLs in hreflang clusters as canonicals. ^{[1]Google Search Console Help. Page indexing report [3]Google Search Central. How to specify a canonical URL with rel="canonical" and other methods} Performance data normally goes to the canonical, but Google notes that in some cases data might be assigned to the actual URL instead, so a few clicks on an alternate are not proof that it is indexed. ^{[5]Google Search Console Help. What are impressions, position, and clicks?} The live test in URL Inspection cannot test this status at all, because Google's canonical choice is determined at indexing time. ^{[4]Google Search Console Help. URL Inspection tool} If you change a canonical and validate the fix, validation typically takes up to about two weeks. ^{[1]Google Search Console Help. Page indexing report}