Direct answer
A canonical link is a strong publisher signal for the preferred representative of duplicate or near-duplicate pages; it is not a command or an indexing guarantee.
Practical steps
- Choose a stable preferred URL.
- Use a self-canonical on indexable originals.
- Align redirects, internal links and sitemaps.
- Remove conflicting canonicals and verify rendered HTML.
Common mistakes
- Canonicalizing translations to English.
- Pointing to non-equivalent pages.
- Leaving mixed internal signals.
Limitations
- Search engines may select another canonical.
- Canonicalization is not a substitute for access or lifecycle design.
Primary sources
- Understand the JavaScript SEO basics — Google Search Central; 2026-03-04; 2026-08-14.