In the context of AMP (Accelerated Mobile Pages), a subdomain endpoint refers to a separate domain or subdomain used to serve AMP versions of your pages, which are optimized for fast loading on mobile devices. These subdomains act as the "endpoint" or the point of access for serving AMP content, allowing your main website (often a non-AMP version) and its AMP version to coexist. Using a subdomain for AMP content is a common practice among publishers and websites that want to separate their AMP content from their regular website content. By doing so, it ensures that the AMP version of the page is served from a different URL, which can help improve performance, keep SEO clean, and provide a better user experience.

Key Concepts of Subdomain Endpoints for AMP:

1. AMP Version on a Subdomain:
   • When you use a subdomain for AMP, the AMP version of your pages will be hosted on a subdomain like amp.example.com (or a similar naming convention). For example:
2. Why Use a Subdomain for AMP?:
   • Performance Optimization: AMP is all about speed, and serving AMP content from a subdomain can help in isolating AMP pages from the rest of your content to improve performance.
   • Clear Separation of Content: Using a subdomain keeps AMP content separate from the regular web pages, making it clear to search engines, users, and the website itself that these pages are optimized specifically for AMP.
   • SEO Benefits: Search engines treat subdomains as separate entities, and using a subdomain can make it easier for search engines to index the AMP versions of your pages without impacting the SEO performance of the regular pages.
   • Simplified Analytics: With AMP hosted on a subdomain, you can easily track AMP traffic separately from regular site traffic through tools like Google Analytics.
3. How Subdomain Endpoints Work with AMP:
   • When implementing AMP on your site, you can either serve AMP content from the same domain (by appending ?amp or /amp to the URL) or from a subdomain. The choice depends on your website's setup, goals, and performance requirements.
   • AMP subdomains are used to ensure that AMP content is served in a clean and optimized environment. The subdomain acts as a dedicated endpoint that serves only AMP content, ensuring fast loading times.
4. Setting Up a Subdomain for AMP: To set up AMP on a subdomain, you will need to take a few steps:
   • Create a Subdomain: Create a subdomain (e.g., amp.example.com) via your hosting provider or DNS settings.
   • Configure AMP for the Subdomain:
     • Install and configure the AMP plugin on your WordPress site or use the AMP framework for other CMS platforms.
     • Depending on your setup, you might need to use a specific configuration to tell the AMP plugin to serve AMP content from the subdomain.
   • Rewrite URLs: Ensure that the AMP version of the page on the subdomain matches the structure of your main site. This means, for example, the page https://www.example.com/post-title would have a corresponding AMP page at https://amp.example.com/post-title.
   • Set Canonical Tags: Make sure that the AMP pages contain proper canonical tags pointing to the non-AMP version of the page. This helps search engines understand the relationship between the two versions and avoid duplicate content issues.
     The AMP page will have a link tag pointing back to the canonical version on the main domain.
   • Testing: After setting up the AMP subdomain, use tools like Google’s AMP Validator to ensure the AMP pages are served correctly and comply with AMP standards.
   • Configure Redirects (Optional): Depending on how you want users to be directed to your AMP content, you may configure your website to automatically redirect users to the AMP version of the page when they access the AMP subdomain.
5. Benefits of Subdomain Endpoints for AMP:
   • Improved Performance: AMP pages often load faster because they’re stripped down and simplified, and hosting them on a subdomain can help with content isolation, caching, and better performance optimization.
   • Better Tracking and Analytics: Using a subdomain allows you to track AMP traffic separately from non-AMP traffic using tools like Google Analytics. This helps you analyze user behavior more effectively.
   • Clear AMP Identification: The subdomain makes it easier for search engines to identify AMP content, improving indexing, ranking, and user experience.

Example of Setting Up AMP on a Subdomain in WordPress:

If you're using WordPress and want to set up AMP on a subdomain, follow these steps:

1. Create the Subdomain:
   • Create a subdomain such as amp.example.com in your hosting or DNS settings. This is where your AMP pages will be served from.
2. Install and Configure the AMP Plugin:
   • Install the AMP for WordPress plugin.