relamphtml

Relamphtml is the commonly used term for the practice of using the HTML link relation rel="amphtml" to point from a canonical page to its Accelerated Mobile Pages (AMP) version. The rel attribute amphtml is a link relation established to help search engines locate the AMP version of a page. It is not an official HTML standard, but it is a widely adopted convention in the AMP ecosystem.

Usage: On the non-AMP canonical page, place in the head: <link rel="amphtml" href="https://example.com/amp/page.html">. This signals to search engines that an AMP-specific page exists at that URL. The AMP page itself typically includes a link rel="canonical" pointing back to the non-AMP page to establish a bidirectional relationship.

Purpose and impact: The primary aim is to enable search engines to serve the faster AMP version in mobile search results, improving perceived performance and potentially influencing rankings. It does not guarantee that AMP will always be served; pages must comply with AMP HTML rules and be valid.

Implementation notes: AMP pages are built with a restricted subset of HTML and AMP JavaScript, and must conform to the AMP project's validation requirements. The canonical/AMP link relationship helps maintain consistency when both versions exist.

Limitations and alternatives: The use of AMP and the amphtml relation is specific to the AMP project. Some sites rely on responsive design or progressive web apps as alternatives to AMP for performance.

See also: canonical URL, Accelerated Mobile Pages, link rel values.

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