This template detects whether it is being used on the mobile version of Wikipedia (i.e., en.wikipedia.org) and adjusts the displayed content accordingly. However, reliance on this template is discouraged. For example, both versions of the content may appear in search engine results, leading to inconsistent or duplicated information. As a general rule, it is recommended to avoid using this template. If layout adjustments are required for mobile compatibility, the preferred approach is to use TemplateStyles and CSS, and read the recommendations for mobile friendly articles.
Rationale
Some features work differently on the mobile website, such as slideshow galleries appearing as ordinary galleries. This template allows better presentation of such content, by e.g. having a "Slideshow" heading when a slideshow is shown, and a "Gallery" heading when a regular gallery is shown.
Usage
{{If mobile|content for mobile website|content for desktop website}}
By default, <span>...</span> tags are used to wrap the specified content. A different tag may be specified using |tag=
E.g. |tag=div can be used if the content contains block-level elements.
Example
Normal usage
{{If mobile|A mobile user you are!|You are looking at the desktop site}}