We all like the Short Message Service; that’s why mobile browsers generally offer the ability to invoke the new SMS window from a link. To do this, we have two possible URI schemes, sms:// and smsto://. Unfortunately, there is no standard way to know for sure which one is compatible with a user’s browser.
The syntax is sms[to]://[<destination number>][?parameters]. As you can see, the destination number is optional, so you can open the SMS composer from the device without any parameters defined. The parameters usually define the body, but this property is not compatible with all phones for security reasons (e.g., to avoid a website sending premium SMS texts). As with sending an email, an SMS is not automatically sent when the user presses the link. The link only opens the SMS Composer window; the user must finish the process manually.