1. 📖 Introduction: Mastering Layered Navigation SEO with the PRG Pattern

Magento 2's layered navigation is an essential tool for user experience, allowing customers to efficiently filter large product catalogs.
However, this powerful feature comes with a severe, often underestimated, technical SEO cost.
By default, every combination of filters, sorting options, and pagination creates a unique, crawlable URL. This leads to a destructive cascade of SEO problems that can undermine your entire site's performance.

The core issue is a multi-faceted threat to your store's visibility:

• (Near-) Duplicate Content:
  Search engines are flooded with thousands of URLs that present nearly identical content, confusing them about which page to rank and diluting the authority of your primary category pages.
• Wasted Crawl Budget:
  Search engines allocate a finite "crawl budget" to every site. When bots spend their time crawling thousands of low-value filter URLs, your truly important pages—like new products or content—may be discovered slowly or not at all.
• Link Equity Dilution:
  Valuable link authority (or "link juice") is passed to these dead-end filter pages, which are often not indexed. This authority is effectively wasted instead of being consolidated on the pages you want to rank.

The JaJuMa PRG Pattern Link Masking extension is engineered to solve this entire chain of problems at its source.
By implementing an elegant and standards-compliant web development pattern, it allows you to regain control over your site's crawlability and indexing, ensuring search engines focus only on the content that matters.

1.1 📝 The Post-Redirect-Get (PRG) Pattern Explained

The power of this extension lies in its intelligent application of the Post-Redirect-Get (PRG) pattern, a well-established and trusted web development technique.
It is not a temporary "SEO hack" but a robust, long-term solution grounded in how the web is designed to work.

To understand its effectiveness, it's crucial to know the difference between two fundamental HTTP requests:

• GET Request:
  Used to retrieve data from a server. When you click a standard link or type a URL in your browser, you are making a GET request. Search engine crawlers follow these links to discover and index pages.
• POST Request:
  Used to submit data to a server, such as filling out a contact form or logging into an account. As a rule, search engine crawlers do not submit forms or follow POST requests, as this could lead to unintended actions.

The JaJuMa extension cleverly repurposes this distinction.
It transforms layered navigation links, which are normally GET requests, into form submissions that use the POST method.
This simple change makes them invisible to search engine crawlers, effectively "masking" them without altering the user experience.

This approach is superior to common but flawed tactics:

• noindex Tag:
  Prevents a page from appearing in search results but does not stop crawlers from visiting it, meaning your crawl budget is still wasted.
• robots.txt Disallow:
  Blocks crawling but can still result in the URL being indexed without content. Furthermore, any link equity pointing to these blocked URLs is lost.
• rel="canonical":
  Helps consolidate ranking signals for duplicate content but does nothing to prevent the initial waste of crawl budget.

The PRG pattern is the only method that solves both the duplicate content and the crawl budget problems simultaneously and safely.

1.2 🔗 How the Extension Optimizes Your Store: The Request Flow

When the extension is active, what appears to be a simple filter click by a user initiates a sophisticated, four-step process in the background that is completely transparent to the shopper but fundamentally changes how search engines see your site.

Let's walk through a typical example:
A user on a "Tops" category page clicks the "Green" color filter.

1. Step 1 (User Action & POST Request):
   The extension intercepts the click. Instead of a standard link (GET request), it triggers a form submission.
   The browser sends a POST request to the server containing the filter data (e.g., color=green).
   This step is completely ignored by search engine bots.

2. Step 2 (Server Redirect):
   The Magento server receives the POST request, processes the filter logic, and then responds not with a webpage, but with a redirect instruction (HTTP 303 See Other).
   This redirect points the user's browser to the final, conventional filtered URL.

3. Step 3 (GET Request):
   The user's browser automatically follows this redirect and makes a standard GET request for the URL provided by the server (e.g., /en/tops-women.html?color=53).

4. Step 4 (Final Page Load):
   The server responds to the GET request by delivering the category page with the "Green" filter applied.
   The user sees the filtered product list, and the URL in their address bar is the correct, shareable, and bookmarkable link.

The result is the best of both worlds:
Search engines are shielded from the thousands of low-value filter combinations, while users and existing backlinks can still use the final, user-friendly URLs without issue.

1.3 🎯 Scope of Optimization

The PRG Pattern Link Masking extension is comprehensive, applying its optimization logic to all the key areas of your product listings that generate problematic URL parameters.

The Post-Redirect-Get pattern is applied to the following functions:

• Layered Navigation:
  All filterable Product Attributes and the Category Filter.
• Grid/List "Sort By" Options:
  e.g., Position, Product Name, Price.
• Grid/List "Show X per Page" Options:
  e.g., 9, 15, 30 products per page.

This ensures all major sources of duplicate content and crawl budget waste from faceted navigation are fully addressed.

1.4 📓 How This Documentation is Structured

This documentation is designed to be a complete resource for users of all skill levels.

• New Users:
  Start here with the Introduction & Core Concepts to understand the powerful SEO principles behind the extension.
• All Users:
  The Configuration & Verification Guide provides a deep dive into every setting and shows you how to confirm the extension is working correctly.
• Developers & Advanced Users:
  Refer to the Advanced Recommendations & FAQ for strategic advice on implementing the extension on live vs. new stores and answers to common technical questions.

1.5 💻 How To Navigate The Extension

All configuration settings for the JaJuMa PRG Pattern Link Masking extension can be found in your Magento Admin Panel.

Navigate to:
JaJuMa -> PRG Pattern Link Masking

From here, you can enable or disable the module's functionality for your entire store.

1.6 📞 Need Help?

Still have questions or need help with your configuration? Our expert team is here to assist. Please don't hesitate to contact our support team for personalized assistance.