How to Fix ‘Alternate Page with Proper Canonical Tag’ in GSC

Let me guess—you logged into Google Search Console, ran a quick check on your indexing report, and there it was: ‘Alternate Page with Proper Canonical Tag’. If you’re anything like most website owners or SEO pros, your first thought might have been, “Is this a problem? Do I need to fix it? And why does it even happen?”

The issue is one of the most common indexing problems in GSC, yet most of the advice available online only provides superficial insights, repeats outdated best practices, or leaves you with more questions than answers.

I get it. Seeing your GSC report flagged with indexing issues can feel like discovering an error message on your car dashboard. You want clarity, you want actionable solutions, and most importantly, you want to make sure that your site’s visibility isn’t quietly suffering because of these alternate canonical tags.

I’m not just going to cover the basics or give you surface-level fixes. We’ll break this down step-by-step. I’ll show you:

• Why this issue happens in the first place
• How to identify if it’s really causing problems
• Proven, real-world fixes that I’ve applied across countless websites

In this guide, we’re going straight to the point. I’ll explain what this issue actually means (without empty promises), why it happens, and—most importantly—how to fix it step by step. No jargon overload, no blurry advice.

If you’re ready to clean up your site’s indexing signals and keep Google happy, let’s dive in.

What Is a Canonical URL?

A canonical URL is an HTML tag (rel=”canonical”) used to tell search engines which version of a page is the preferred or “master” version when there are duplicate or similar pages. It’s essentially a signal to search engines saying, “This is the main version of this content; please focus on this one.”

For example, if you have the same blog post accessible at /blog/post and /blog/post?ref=123, the canonical tag tells search engines which one should be considered the primary URL.

The Purpose of Canonical Tags in SEO

Canonical tags prevent duplicate content issues that can confuse search engines and decrease your ranking potential. Without a canonical tag, search engines might index multiple versions of the same content, spreading out link equity and making it harder for any single version to rank well.

Image source

Google treats the canonical tag as a strong hint rather than an absolute directive. If Google agrees that the specified canonical URL is the most relevant version, it will consolidate ranking signals and display that URL in search results.

However, if Google detects inconsistencies—like conflicting canonical tags or sitemap errors—it might ignore the tag and choose a canonical URL on its own.

Let’s break down the key conditions with simple explanations and sample code.

Self-Canonical (Correct Usage)

A self-referencing canonical tag points to the same URL as the current page. This is the best practice for standard pages to make sure search engines understand the URL as the authoritative version.

When to use it:

• When the page is unique and doesn’t have duplicates.
• To prevent issues caused by URL variations (e.g., query parameters like ?utm_source).

Sample Code:

The product page https://www.example.com/product-page contains a self-canonical pointing to itself. This eliminates confusion caused by URL parameters like ?ref=affiliate123.

Canonicalized (Pointing to Another URL)

A canonicalized page points to another URL as the preferred version. This is commonly used when multiple pages have similar content, and you want to combine their ranking signals.

When to use it:

• When you have multiple product pages with slight variations (e.g., color or size).
• When you have both HTTP and HTTPS versions of a page.
• When content is syndicated across multiple sites.

Sample Code:

On https://www.example.com/product-page-red, you might see:

Example Scenario:

You have two product URLs:

• https://www.example.com/product-page-red
• https://www.example.com/product-page-blue

If both have nearly identical content, you canonicalize them to https://www.example.com/product-page to avoid duplicate content issues.

Missing Canonical Tag (No Canonical Set)

When there’s no canonical tag, search engines must decide on their own which version of the page to rank. This often leads to duplicate content issues and inconsistent indexing.

When it happens:

• Pages are created dynamically (e.g., product filters).
• The canonical tag was overlooked during development.
• Content management systems (CMS) didn’t generate it automatically.

Sample Code:

(No <link rel=”canonical”> tag present in the <head> section.)

Example Scenario:

• https://www.example.com/product-page?color=red
• https://www.example.com/product-page?color=blue

Without a canonical tag, search engines might index both URLs as separate pages creating duplicate content problems.

Causes of the ‘Alternate Page with Proper Canonical Tag’ Issue

If you’ve come across the ‘Alternate Page with Proper Canonical Tag’ warning in Google Search Console, you might be wondering what it means and if it’s affecting your SEO. Don’t worry—it’s not always a red flag. Let’s dive into the key reasons this issue arises and whether it requires your attention.

WWW vs. Non-WWW Versions

One common reason behind the ‘Alternate Page with Proper Canonical Tag’ Issue is the WWW vs. Non-WWW version conflict.

Your website can technically exist in two formats:

https://www.example.com
https://example.com

Of course, they might look identical to most users, but search engines treat these as two separate websites unless they are properly configured. If both versions are accessible and indexable without redirects or canonical tags, Google may get confused about which version to prioritize.

For example:

If your canonical tag points to the non-WWW version but the WWW version is also indexed, Google will treat one as an “alternate” version of the other.

Why Does This Happen?

• Improper Canonicalization: Both WWW and non-WWW versions are accessible and serve the same content, but only one is marked as the canonical version.
• Missing Redirects: The non-canonical version isn’t redirected to the preferred one.
• Inconsistent Internal Linking: Some internal links point to the WWW version, while others point to the non-WWW version.
• Backlinks and External Links: External websites might link to both versions, causing mixed signals for search engines.

How to Check if Your Site Has This Issue

a. Manual Check:

• Open a browser and type both:
  • https://www.example.com
  • https://example.com
• See if one redirects to the other. If they load independently without redirection, you have an issue.

b. Use Google Search Operators:

• Type site:example.com and site:www.example.com into Google.
• Check if both versions return indexed results.

c. Check in Google Search Console:

• Go to Indexing → Pages.
• Look for “Alternate Page with Proper Canonical Tag.”
• Click on the affected URLs to see if they are split between WWW and non-WWW versions.

d. Use an online WWW redirect checker

How to Fix the WWW vs. Non-WWW Issue

a. Choose Your Preferred Version:

• Decide whether you want to use WWW or non-WWW as your primary domain.
• This is often a branding or technical choice, but consistency is key.

b. Implement 301 Redirects:

• Use 301 permanent redirects to point all traffic from one version to the other in your .htaccess file (Apache) or nginx.conf (Nginx).

Example for .htaccess (Apache):

Example for nginx.conf (Nginx):

⚠️ Things to Double-Check:

Make sure your SSL certificates are properly installed and referenced (ssl_certificate, ssl_certificate_key).

Verify that the DNS settings for www.example.com and example.com are correctly pointed to your server.

c. Set the Preferred Domain in Google Search Console:

• Google no longer lets you set a preferred version directly in GSC, but you can still verify both versions and ensure canonical tags are correctly configured.

d. Update Canonical Tags:

• Make sure all pages use the correct canonical tag pointing to your preferred version.

Make sure all internal links consistently point to the preferred version (WWW or non-WWW). If possible, reach out to high-authority websites linking to the incorrect version and ask them to update their links. Make sure your XML sitemap only includes URLs from your preferred domain version.

After implementing these steps use a tool like Screaming Frog or Ahrefs Site Audit to make sure all redirects are working correctly and monitor GSC regularly to see if the “Alternate Page with Proper Canonical Tag” warnings decrease.

Pagination Issues

Pagination occurs when content is split across multiple pages, often seen in URLs like /blog/page/2/ or /products?page=3. These pages usually share a significant amount of content structure, such as headers, titles, and meta descriptions, leading Google to see them as duplicate or near-duplicate content.

This creates a problem because Google might prioritize the first page of your pagination series and ignore valuable content hidden deeper in the paginated set.

How to Check if Your Site Has Pagination Issues

Go to Indexing > Pages in GSC. Look for entries marked as “Alternate Page with Proper Canonical Tag.” Review the listed URLs to see if they include pagination patterns (/page/2/, ?page=3).

Use the URL Inspection Tool in GSC to check if paginated URLs have a canonical tag pointing to the main page (/blog/ or /products/).

If every paginated page points to the main page as canonical, it could prevent Google from properly indexing deeper content.

Check if rel=“prev” and rel=“next” tags are properly implemented (though Google no longer officially uses them, they still help for clarity). Make sure paginated pages have internal links pointing to deeper content instead of looping back to the main archive page.

How to Fix Pagination Issues

Instead of setting every paginated page to canonicalize to /blog/ or /products/, allow each paginated URL (/blog/page/2/, /blog/page/3/) to self-canonicalize.

This tells Google that each page is intentionally part of a sequence and deserves individual indexing.

Avoid infinite scrolling without a “view all” option, as it can prevent crawlers from accessing deeper content. If your content can reasonably fit on a single page, offer a “View All” option. Canonicalize paginated URLs to the “View All” version.

In some cases, if deeper paginated content doesn’t hold unique value, you can set them to “noindex, follow” in the meta robots tag. However, be careful, though, as this can cause orphaned pages if you don’t handle it properly.

Duplicate Content Across Multiple URLs

Duplicate content occurs when multiple URLs display identical or highly similar content, causing search engines to struggle to determine which version to rank in search results. In response, Google may automatically choose a canonical version—the URL it considers the “main” one—and label the others as “Alternate Page with Proper Canonical Tag” in Google Search Console (GSC).

This issue is common on eCommerce websites, where product pages can be accessed through multiple URLs due to variations like sorting filters, category paths, or tracking parameters. For instance:

• example.com/product/red-shoes
• example.com/category/footwear/red-shoes
• example.com/product/red-shoes?utm_source=newsletter

Yep, these URLs point to the same content but Google may decide one is the primary (canonical) version and mark the others as alternates.

How to Check if Your Site Has This Issue

Google Search Console (GSC):

Navigate to the Indexing > Pages report. Look for pages marked as “Alternate Page with Proper Canonical Tag.” Review the list to identify patterns or problematic URLs.

You can also use site:yourdomain.com in Google with fragments of duplicate content or specific URLs, then compare indexed URLs to see if duplicates are appearing.

How to Fix Duplicate Content Issues

You can use canonical tags to make sure each duplicate URL points to the preferred canonical version using the <link rel=”canonical” href=”https://example.com/preferred-page”/>  tag in  the <head> section.If duplicates serve no real purpose, set up 301 redirects to the primary URL. For product variations (e.g., colors or sizes), use canonical tags to point all variants to a single product page, or implement parameter-based rules.

HTTP vs. HTTPS Versions

If your website has both HTTP (non-secure) and HTTPS (secure) versions accessible, search engines may view them as two separate URLs, even if they display the same content.

For example:

• http://example.com/page
• https://example.com/page

In an ideal setup, all HTTP traffic should redirect to HTTPS versions using 301 redirects, and the canonical tag on each page should point explicitly to the preferred HTTPS version. However, if these steps aren’t properly implemented, Google might see both versions as valid, index them separately, and then flag the HTTP version as an alternate page with a proper canonical tag pointing to the HTTPS version.

Best Practices to Fix the Issue

1. Set Up 301 Redirects: Make sure all HTTP pages redirect permanently to their HTTPS counterparts.
2. Update Canonical Tags: Double-check that every HTTP page has a canonical tag pointing to the correct HTTPS URL.
3. Check Sitemap and Robots.txt: Make sure your sitemap only includes HTTPS URLs and that no HTTP pages are unintentionally blocked in the robots.txt file.
4. Update Internal Links: Double-check all internal links and make sure to use HTTPS instead of HTTP to prevent confusion during crawling.

Trailing Slash Inconsistencies

One of the common reasons Google Search Console (GSC) might flag a page as an “Alternate Page with Proper Canonical Tag” is due to trailing slash inconsistencies in your website’s URLs. In simple terms, a trailing slash refers to the “/” at the end of a URL.

For example:

• https://example.com/page/ (with trailing slash)
• https://example.com/page (without trailing slash)

These URLs may seem exactly the same to users. However, search engines treat them as two distinct URLs. If both variations exist and are accessible, Google must decide which one is the “canonical” version—the preferred URL to display in search results.

When this inconsistency isn’t handled properly, both versions may end up being indexed or flagged in GSC. For instance, if /page/ is set as the canonical version but /page is also accessible, Google might mark /page as an alternate version with the canonical pointing to /page/.

How to Fix Trailing Slash Inconsistencies

• Set a Consistent URL Structure: Decide whether your website will use trailing slashes or not, and stick to it site-wide.
• Use 301 Redirects: Redirect the non-preferred version (e.g., /page) to the preferred one (/page/) or vice versa.
• Update Canonical Tags: Make sure every page has a self-referencing canonical tag pointing to the preferred version.
• Update Internal Links: Audit your internal linking structure and confirm all internal links consistently point to the canonical version.

CMS and Theme-Related Issues

The default settings, plugins, or even themes of famous content management systems (CMS) like WordPress, Shopify, or Wix can unintentionally create duplicate or alternate versions of your pages. This often happens when the CMS automatically generates paginated URLs, tag pages, or category archives without proper canonicalization settings.

For example, a blog post might exist at multiple URLs:

• /blog/post-title/
• /blog/post-title/?utm_source=newsletter
• /blog/category/post-title/

These URLs technically point to the same content, but the CMS might not set the canonical tag correctly, or the theme might override global settings, leading Google to flag them as “Alternate Page with Proper Canonical Tag.”

In some cases, poorly coded themes can also generate unnecessary URL parameters or duplicate content paths. For instance, search or filter functionalities on eCommerce websites can produce multiple variations of the same product page (?color=red, ?size=medium) without pointing them to the primary version with a canonical tag.

Plugins you use for SEO or caching can further complicate things. Sometimes, two plugins might conflict with each other, causing incorrect canonical URLs to be applied across pages. Additionally, CMS themes with built-in SEO settings can conflict with plugins like Yoast SEO or Rank Math, leading to inconsistencies in canonical tags.

How to Diagnose the Issue

Start with the HTML source code of the affected pages. Open the page in your browser, right-click, and select “View Page Source” or press Ctrl+U. Search for the canonical tag using Ctrl+F and type rel=”canonical”. The tag should look like this:

Make sure:

• The canonical tag points to the correct primary URL.
• There is only one canonical tag on the page.
• The canonical tag is not pointing to itself unintentionally unless it’s the main version of the page.

Tools for HTML Inspection:

• Browser Developer Tools (Chrome DevTools)
• Ahrefs Site Audit
• Screaming Frog SEO Spider

If the canonical tag is in both the HTML and HTTP headers but points to different URLs, search engines may receive conflicting signals, which could result in indexing the wrong page.

Next, head over to Google Search Console (GSC) under Indexing > Pages and look for the “Alternate Page with Proper Canonical Tag” issue. Click on the affected URLs and check:

• Which URL Google has selected as the canonical version.
• If your declared canonical matches Google’s chosen canonical.

If they differ, you’ll need to revise your implementation. Additionally, perform a site search query (site:example.com/page) in Google to see if the correct canonical version is appearing in the search results.

During the audit, check for scenarios like:

• Multiple pages point to each other instead of one primary URL.
• Pages with canonical tags pointing to non-existent URLs.
• Canonical URLs that lead to a 404 error.

Remember, sometimes, deployment errors cause canonical mismatches in live environments. Use tools like Google’s URL Inspection Tool in Search Console or Screaming Frog’s “View Source Live” option to check canonical tags in real time.

If the issue occurs on paginated pages (e.g., /blog/page/2/), make sure canonical tags are set correctly.

• Page 2, 3, etc., should not canonicalize to the main /blog/ page unless specifically intended.
• Use rel=”next” and rel=”prev” tags correctly alongside canonical tags.

Advanced Tips and Insights

I know it’s easy to assume that adding a single line of code will solve everything. But in reality, implementing canonical URLs correctly is one of the more nuanced aspects of SEO. Now, I’ll share advanced techniques to address canonicalization challenges, especially in complex scenarios

Handling Multi-Language and Hreflang Tags

Multi-language websites often struggle with canonicalization because of the overlap between hreflang and canonical tags. Each language version should have a self-referencing canonical tag, while the hreflang attribute signals alternate versions for different regions or languages.

For example:

• Self-referencing canonical: /en/page/ → canonical points to /en/page/
• Hreflang alternate for Spanish: /es/page/ → canonical points to /es/page/

A common mistake is pointing all language versions to a single canonical URL (e.g., /en/page/). This tells Google to ignore alternate versions and index only the English version. So, always confirm that hreflang tags and canonical tags align properly.

Canonical Tags in JavaScript-Rendered Content

If your website relies on JavaScript frameworks (e.g., React, Angular, or Vue), canonical tags can sometimes fail to render properly for search engines. While Google claims it can process JavaScript effectively, there’s often a gap between what’s promised and what’s indexed.

To avoid this:

• Server-Side Rendering (SSR): Make sure canonical tags are rendered on the server side rather than being dynamically generated in the browser.
• Validation Tools: Use tools like Google’s URL Inspection Tool to verify that the canonical tag is present in the rendered HTML, not just in the raw code.

For mission-critical pages, manual verification with tools like View Rendered Source Chrome extension can confirm proper rendering.

Dealing with Syndicated Content

Content syndication (e.g., republishing your blog posts on third-party platforms) often introduces canonical tag confusion. If multiple websites publish the same content without proper canonicalization, Google may struggle to determine the original source.

Similar Issues on GSC

We’ve already covered the “Alternate Page with Proper Canonical Tag” issue in detail, but it’s worth noting that Google Search Console (GSC) often flags other related indexing and canonicalization problems.

In this section, I’ll briefly walk you through a few of these common related errors you might encounter in your GSC report. The good news? Most of them can be resolved using the same principles we’ve discussed earlier

So, let’s dive into these related issues and clear up any confusion, one error at a time.

‘ Duplicate, Google Chose Different Canonical Than User ’ in GSC

The ‘Duplicate, Google Chose Different Canonical Than User’ issue in Google Search Console (GSC) means that Google has found multiple pages with similar content, and instead of using the canonical URL you specified, it decided to index a different version it considers more appropriate.

Yes, sometimes there might be inconsistencies between your declared canonical tag, internal links, and sitemap entries.

‘ Duplicate Without User-Selected Canonical ’ in GSC

The “Duplicate without user-selected canonical” issue in GSC means that Google has detected multiple pages on your website with similar or identical content, but none of them have a canonical tag telling Google which version should be considered the primary one for indexing.

Why This Happens:

• Duplicate content exists across multiple URLs (e.g., with and without parameters like ?utm_source).
• There’s no rel=”canonical” tag specified on any of the pages, leaving Google to guess which version is the primary one.
• URL variations caused by filters, tracking parameters, or session IDs might trigger this issue.

Why It’s a Problem:

• Google may choose the wrong version of the page to index.
• Link equity could be split between duplicate URLs, weakening SEO effectiveness.
• Search engines may waste the crawl budget on unnecessary duplicates instead of focusing on more valuable pages.

What Happens If I Ignore the Warning?

If you ignore the warning, search engines might struggle to understand which version of your page to index and rank. This can lead to duplicate content issues, where multiple versions of the same page compete against each other in search results.

However, if you’ve intentionally set up canonical URLs—for example, on paginated pages, localized content, or specific URL variants—it’s usually nothing to worry about. The warning is just a reminder to double-check that everything aligns with your intended strategy.

How Long Does It Take for GSC to Validate Canonical Fixes?

When you submit canonical fixes in Google Search Console (GSC), it typically takes a few days to a couple of weeks for Google to validate the changes. The timeline depends on factors like crawl frequency, the size of your website, and how often Googlebot visits the affected pages.

For smaller websites, validation might happen faster, sometimes within a few days. However, on larger sites with thousands of URLs, it could take several weeks.

Can I Have Multiple Canonical Tags on One Page?

No, you should not have multiple canonical tags on one page. Google and other search engines expect a single canonical tag to clearly indicate the preferred version of the page. When multiple canonical tags are present, search engines may get confused, ignore them entirely, or pick one at random, which could undermine your SEO efforts.

If you’re trying to reference multiple URLs, you likely have an issue with your setup. Double-check your page’s source code and make sure only one rel=”canonical” tag is present, pointing to the most relevant, authoritative version of the page.

Do Canonical Tags Work Across Domains and Subdomains?

Yes, canonical tags can work across domains and subdomains, but they need to be implemented correctly to be effective. When you’re dealing with duplicate or highly similar content across different domains (e.g., example.com and example2.com) or subdomains (blog.example.com and shop.example.com), canonical tags tell search engines which version of the page should be treated as the primary one.

However, search engines treat cross-domain canonicals more as a strong suggestion rather than a directive.