## TL;DR

When one piece of content lives on multiple URLs, pick one canonical (usually your own domain) and point every copy at it with a canonical link tag. Verify the tags are actually in the HTML head of each copy. Without canonicals, search engines split the ranking signals across duplicates and none of them rank well.

```text
canonical URLs when cross-posting the same content
```

## Use this when

- Syndicating articles across platforms
- The same content exists at multiple URLs
- Consolidating ranking signals

## Not for this skill when

- The copies are substantially different (they are not duplicates)
- You do not control the copies (request, do not assume)
- The goal is ranking every copy (pick one winner instead)

## Steps

1. Choose the canonical. Your own domain wins by default; it is the asset you keep. Expected: one URL designated before any copy goes live.

2. Add the canonical tag to every copy. A link tag in the head pointing at the canonical URL, on every duplicate including the canonical itself. Expected: the tag present on all versions.

```
in the page head, one line:
  link rel="canonical" href="https://example.com/the-article"
```

3. Use platform canonical fields where they exist. dev.to and others have a canonical URL setting; use it instead of hoping. Expected: platform-level canonical set, not just wished for.

4. Verify in the rendered HTML. Fetch each copy and check the head; CMS plugins and platform quirks drop tags silently. Expected: confirmed tags on every copy.

5. Watch Search Console. The canonical report shows which URL Google honored; mismatches mean a tag problem. Expected: the chosen canonical is the indexed one.

## Variant phrasings

### canonical tag for syndicated content

One canonical, link tags on every copy, verified in HTML, confirmed in Search Console.

### avoiding duplicate content when cross-posting

Canonicalize every copy to the original on your domain.

### which URL should be canonical

Your own domain, by default. Platforms are distribution.

## Why it happens

Search engines penalize no one for duplicates, but they do split ranking signals across copies, so each ranks worse than one consolidated page would. The canonical tag is how you tell them to consolidate.

## Edge cases / pitfalls

- Canonical is a hint, not a command; Google can ignore it if the copies differ too much.
- Do not canonicalize to a URL that 404s or redirects; that orphans every copy.
- Self-referencing canonicals on the original are correct and expected.
- Check after every CMS update; plugins love to drop head tags.

## Provenance

Resolved from the public thread: https://vectle.com/posts/pst_3O5NdzwOA6qKx3pb2Om2tg