Teardown
Missing canonical tags are usually fine. Wrong ones are not.
Audit tools flag both. Google's own documentation says one of them is usually fine.
On this page
18 of the 42 startup sites I audited had pages with no canonical tag: 43%. 12 had pages whose canonical pointed at a different page: 29%.
Most audit tools flag the first one loudly. It is the second one that deserves the attention.
What I found
42 startup sites, 14,023 pages, crawled 15 to 18 September 2026
- No canonical
- 18 of 42 sites (43%), 12 pages on the median affected site
- Canonical pointing elsewhere
- 12 of 42 sites (29%), 4 pages on the median affected site
- How they were compared
- Trailing slashes, http or https, and www were ignored, so /about and /about/ do not count as a mismatch
What a canonical tag does
A canonical tag is a line in a page's code naming the address that should be treated as the real version of that page. It exists for duplicates: the same product reachable at two addresses, or a page with tracking codes on the end.
Missing: Google says you will likely be fine
This surprises people, but it is in Google's own documentation on canonicalization:
While we encourage you to use these methods, none of them are required; your site will likely do just fine without specifying a canonical preference.
Google Search Central, canonicalization
Without a tag, Google chooses a version itself. For a site with no real duplicates, that is the page itself. So I treat a missing canonical as low priority, unless the site genuinely has the same content at several addresses.
Wrong: a strong signal pointing the wrong way
A canonical that names a different page is another matter. The same documentation describes the tag as:
A strong signal that the specified URL should become canonical.
Google Search Central, canonicalization
In other words, a page whose canonical names another page is asking Google to show that other page instead. When it is deliberate, for a real duplicate, that is correct. When it is a template mistake, a real page is asking to be left out.
The common mistake is a template that writes the same canonical on every page of a section, usually the section's own index. Every article in it then points at the listing.
Check your own site, no code needed
- Once Search Console is set up, paste the address of an important page into the URL Inspection box at the top.
- In the result, look at the Google-selected canonical field under Page indexing.
- If it shows a different address from the one you inspected, Google is treating another page as the real version. Check whether you meant that.
- Repeat for one page of each type. A template mistake shows up on all of them.
What to ask your developer
- Does each page's canonical point at itself, unless it is a real duplicate?
- Is the canonical written by a template? If so, where does it take the address from?
What I could not tell from outside
A canonical is a hint, not an order. Only Search Console shows which version Google actually chose, and I had no Search Console access to any of these sites.
These are counts on 42 startup sites I audited from the outside, mostly developer tools and SaaS. They are not an industry average, and nothing here measured whether any of these sites performed worse in search because of what I found.
Want to know which of these your site has?
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