If a website displays a phone number behind a call button, what should happen when someone clicks it on a laptop? On a MacBook, it may open the configured phone or calling app, but I'm not sure how consistent that behavior is across Windows and other desktop systems. Is it reasonable to expect most laptop users to have an application that can handle a telephone link? If the laptop has no suitable app, should the site show the number, copy it to the clipboard, hide the call button, or provide another fallback?
4 Answers
A common responsive approach is to show a prominent Call button on touch-oriented devices and the formatted phone number on larger screens. Both can still use a `tel:` link, but desktop visitors get useful information even if clicking the link opens nothing or launches an unexpected app.
On laptops, a `tel:` link may do nothing or open an installed VoIP application such as a conferencing or calling client. Most desktop users probably won’t expect a call to start automatically, so exposing the number and possibly offering a copy-to-clipboard action is better than relying entirely on the link.
Keep the `tel:` link for phone users, but don’t make it the only way to access the number on a laptop. Display the phone number as normal text beside the button so desktop users can copy it or dial from another device. You can also offer email or a contact form as a fallback.
Use a standard `tel:` link and let the operating system decide which application handles it. The browser will pass the link to the configured calling app, if one exists. There isn’t a universal way for the website to control or reliably detect what will happen, and the syntax is `tel:number`, not `tel://number`.
It works much like a `mailto:` link: the operating system or browser uses whichever compatible application or web app is configured.