Is duplicate content hurting your SEO performance? At PEAKONTECH, we often find that many websites unknowingly suffer from duplicate URL issues — diluting their rankings and confusing search engines. The solution? The Canonical Tag. This essential HTML element tells Google which version of a page is the original, consolidating SEO signals and preventing ranking conflicts.
In this comprehensive guide, We explains what canonical tags are, why they matter, and how to implement them correctly — whether you’re using plain HTML or popular tools like Yoast and Rank Math in WordPress.
Let’s help your website stay clean, crawlable, and SEO-optimized!
What is a Canonical Tag?
A Canonical Tag is a piece of HTML code that you use on your website to tell search engines:
“This page is the original (main) version of the content, and others are duplicates or similar versions.”
Why Use a Canonical Tag?
Often, the same content appears on multiple URLs. This can confuse Google — which URL should it rank?
The Canonical Tag solves this issue by clearly telling Google:
“This is the original link. Ignore the rest.”
Benefits of Using a Canonical Tag:
- Prevents duplicate content issues
- Ensures Google ranks only the original page
- Keeps your SEO performance strong
How to Use a Canonical Tag?
Add the following code inside the <head> section of your HTML:
<link rel=”canonical” href=”https://example.com/main-page/” />
This tag tells Google that the preferred or original version of the page is:
https://example.com/main-page/
Example Scenario:
You have 3 similar pages:
- Main Page: example.com/mobile-one
- Duplicate Page 1: example.com/mobile-two
- Duplicate Page 2: example.com/mobile-three
You want Google to only rank /mobile-one and treat the other two as duplicates.
Solution: Add Canonical Tag
- On mobile-two, add this inside <head>:
<link rel=”canonical” href=”https://example.com/mobile-one” />
- On mobile-three, add the same:
<link rel=”canonical” href=”https://example.com/mobile-one” />
Where to Add the Canonical Tag?
- If using raw HTML → Manually insert in the <head> section
- If using WordPress:
- Yoast SEO plugin → Edit Page → Advanced → Set Canonical URL
- Rank Math SEO → Edit Page → Advanced → Add Canonical URL
- Yoast SEO plugin → Edit Page → Advanced → Set Canonical URL
What Will Happen?
- Google will understand mobile-one is the main/original page
- mobile-two and mobile-three won’t compete in rankings
- You’ll avoid duplicate content problems
- SEO value will be concentrated on one URL
QNA
Q: What is a canonical tag?
A: An HTML element (<link rel=”canonical” href=”URL”/> in the <head>) that tells search engines which URL is the “master” version of duplicate/similar pages.
Q: What is a canonical URL?
A: The preferred version of a URL that search engines should index (e.g., example.com/page instead of example.com/page?session=123).
Q: What is a canonical URL in SEO?
A: The URL designated as the primary version to consolidate ranking signals and avoid duplicate content penalties.
Q: What is a non-canonical URL?
A: A duplicate or alternate URL that points to the canonical URL (e.g., URL parameters, HTTP vs HTTPS, or www vs non-www versions).
Q: What is a self-referential canonical tag?
A: A canonical tag pointing to its own URL (e.g., <link rel=”canonical” href=”https://example.com/current-page”/>), signaling it’s already the preferred version.
Q: What is an alternate tag vs. canonical tag?
A:
- Canonical: Marks the primary URL for search engines.
- Alternate (e.g., hreflang): Specifies language/regional variants (e.g., example.com/en vs example.com/es).
Q: Why is canonical important in SEO?
A: Prevents duplicate content issues, consolidates ranking signals, and ensures the correct page is indexed.
Q: What does canonical do?
A: Directs search engines to the “main” version of a page, avoiding indexation of duplicates.
Q: What is the main purpose of a canonical tag?
A: To resolve duplicate content by specifying which URL should rank in search results.
Q: Do canonical tags affect SEO?
A: Yes! They prevent ranking dilution, improve crawl efficiency, and fix duplicate content.
Q: Are canonical URLs bad for SEO?
A: No, when used correctly. Misuse (e.g., pointing to wrong URLs) can harm SEO.
Q: How important are canonical tags?
A: Critical for large sites with duplicate content (e.g., e-commerce filters, session IDs).
Q: How to create a canonical tag?
A: Add this to your <head>:
<link rel=”canonical” href=”https://example.com/canonical-page/” />
Q: How to set a canonical URL?
A: Via:
- HTML tags (as above).
- HTTP headers (for non-HTML files like PDFs).
- Sitemaps (Google may use it as a hint).
Q: How do I add a canonical tag for SEO?
A: Insert the tag in your CMS (e.g., WordPress SEO plugins) or directly in the HTML.
Q: When to use a canonical tag?
A: For:
- Duplicate content (e.g., printer-friendly pages).
- URL parameters (e.g., sorting/filtering).
- Syndicated content.
Q: Do I need a canonical tag?
A: Yes if you have duplicates. Self-referential canonicals are optional but recommended.
Q: Can a canonical URL be relative?
A: Yes (e.g., /page), but absolute URLs (full https:// paths) are preferred for clarity.
Q: How to check canonical tags?
A: Use:
- View Page Source (look for <link rel=”canonical”).
- Google Search Console (URL Inspection tool).
- SEO tools (Ahrefs, Screaming Frog).
Q: How do I find canonical tags on my website?
A: Crawl your site with Screaming Frog or use browser DevTools (Elements tab).
Q: How to test canonical tags?
A: Check if Google recognizes them via:
- Google Search Console > URL Inspection.
- Rich Results Test tool.
Q: What is an example of canonicalization?
A: Google indexing example.com/dress instead of example.com/dress?color=red due to a canonical tag.
Q: How to fix canonical tags?
A: Ensure:
- The tag points to a valid, indexable URL.
- No chains (e.g., Page A → Page B → Page C).
- No 404 canonicals.
Q: How do I fix canonical issues in SEO?
A: Audit with tools like Screaming Frog, then:
- Correct broken/misdirected tags.
- Use 301 redirects if needed.
Q: What is a canonical issue in SEO?
A: Common problems:
- Missing tags on duplicates.
- Multiple canonicals on one page.
- Canonicals pointing to blocked/noindex pages.
Q: What is canonical and non-canonical?
A:
- Canonical: The primary URL (ranked in search).
- Non-canonical: Duplicates that pass signals to the canonical.
Q: What is canonical SEO?
A: Best practices to manage duplicate content via canonicals (tags, redirects, hreflang).
Q: What is a canonical query string? (SEO impact)
A: A URL parameter (e.g., ?sort=price) that’s canonicalized to the main URL to avoid duplicates.
Q: What is a canonical domain? (SEO context)
A: The preferred domain version (e.g., https://example.com vs http://www.example.com), set via:
- Canonical tags.
- 301 redirects.
- Google Search Console settings.
PEAKONTECH is a data-driven digital marketing agency offering full-stack services including SEO, paid ads, web design, CRO, and e-commerce development. From Shopify to WordPress, and from social media to automation — our team helps brands grow smarter and scale faster across every digital touchpoint.
