Potential Issues with Canonical URLs Implemented via HTML and JavaScript
Introduction
Hello everyone,
Firstly, a huge thank you for all your assistance so far—it has been invaluable to us. Today, I want to discuss an issue we’re facing regarding canonical URLs on our Magento 2 sites.
The Setup
Currently, we have a canonical URL implemented in the HTML <head> section and another generated by JavaScript. Our concern arises from the fact that tools like the “SEO with 1 Click” Chrome extension seem to pick up the JavaScript version.
The Problem
In some scenarios, such as with pagination and filtering, the HTML canonical URL may differ from the JavaScript-rendered one. This leads to a critical question: Could this discrepancy lead to significant indexation issues for our paginated pages?
Considerations
One of our developers put significant effort into creating the JavaScript version. However, I’m considering whether it might be more beneficial to rely solely on an HTML canonical. This way, the canonical would update accurately on paginated pages, ensuring each page has a unique canonical URL, which might aid in better indexation.
Key Questions
- Is having multiple canonical URLs a fundamentally bad practice?
- Is relying on JavaScript to insert canonical URLs problematic?
Current SEO Performance
We enjoy strong rankings for most of our main keywords, so any changes need to be carefully considered to avoid negatively impacting our major sites (UK, USA, etc.) as we transition to Magento 2.
Conclusion
Thank you for taking the time to read this. I’m eager to hear your insights!
Update
After speaking with another developer this morning, I’ve learned that we don’t actually have two separate canonical URLs. The JavaScript is merely updating the same canonical when pagination occurs. This explains the different canonical URL observed when JavaScript is disabled.
Your feedback would be greatly appreciated!
2 responses to “Canonical URLs via HTML and JS: Potential Problems?”
Understanding Canonical URLs and Their Impact
Canonical URLs are important for SEO as they inform search engines about the preferred version of a webpage when there are multiple pages with similar content. Correct implementation ensures that search engines index the desired page, avoiding issues like duplicate content, which can dilute your SEO efforts.
Potential Issues with JS and HTML Canonicals
Consistency and Source of Truth: Ideally, your canonical URL should be consistent across both HTML and JavaScript. If JS alters the canonical URL, it could create confusion for search engines, as they might encounter different canonical tags at different times.
Rendering and Indexing: Search engines primarily process HTML content. Although Google and other search engines have improved their ability to execute JavaScript, there is still a significant dependency on HTML. If the canonical URL is set or altered by JS, there’s a risk that search engines might not interpret it correctly or at all if they don’t render the JavaScript.
Speed and Efficiency: Using JavaScript to set canonical URLs can also introduce delays because the page must be fully rendered before the canonical URL is processed. This can lead to potential issues, especially if the JS doesn’t load correctly or is blocked for some reason.
Best Practices and Recommendations
Rely on HTML for Canonicals: It’s generally more reliable to set canonical URLs in HTML rather than rely on JavaScript. This ensures that search engines and other tools pick up the correct URL immediately without needing to execute scripts.
Unique Canonicals for Paginated Content: When dealing with pagination, make sure each page has a unique canonical URL reflective of its content to improve indexation chances and visibility. Using HTML for this ensures consistency and clarity.
Avoid Multiple Canonicals: Having multiple or changing canonical URLs can confuse search engines and undermine your SEO strategy. Ensure there’s a single, consistent canonical URL for each page.
Testing and Validation: Use tools like Google Search Console and browser extensions (like the “SEO with 1 click” tool you mentioned) to verify which canonical URLs are being recognized. Disable JavaScript in your browser to see if canonical URLs are appropriately set in HTML.
Review JavaScript Necessity: If JavaScript is altering the canonical URL unnecessarily, consider revisiting whether it’s needed or whether it can be streamlined.
Consult with SEO Experts: Since your sites are performing well with important keywords, it’s crucial to make
Thank you for sharing your insights on the challenges surrounding canonical URLs in your Magento 2 setup! This is indeed a crucial topic, especially for maintaining strong SEO performance.
It’s great to hear that your team has been proactively considering the implications of using JavaScript to manage canonical URLs. To address your concerns, it’s worth noting that while using JavaScript to set canonical URLs isn’t inherently problematic, it does come with caveats. Search engine crawlers have been improving in their ability to execute JavaScript, but there may still be instances where they don’t render the page as expected. This can lead to potential discrepancies, especially around critical functionalities like pagination.
Given your update clarifying that both HTML and JavaScript manipulate the same canonical URL, it might be beneficial to strategize around making sure your HTML canonical is always the authoritative version. This means ensuring that the HTML version reflects the correct canonical logic upfront, particularly for paginated and filtered content.
As for your question about multiple canonicals, having varied canonicals can confuse search engines and may dilute the authority of the intended pages. It’s generally best practice to ensure there’s only one canonical URL per page, which leads to clearer signals for indexing.
In summary, try to limit reliance on JavaScript for crucial SEO metadata like canonical URLs. Instead, consider implementing a server-side rendering solution that defines the correct canonical links in the HTML markup. This will help safeguard your strong rankings as you transition to Magento 2 and mitigate the chances of indexation