How to trigger a phone call when clicking a link in a web page on mobile phone

I need to build a web page for mobile devices. There's only one thing I still haven't figured out: how can I trigger a phone call through the click of text?

Is there a special URL I could enter like the mailto: tag for emails?

Device specific solution are not preferred.

I know iPhone automatically recognizes phone numbers and creates a link for this, but it would be great if this could be done for images too... and also for most mobile devices.

Most modern devices support the tel: scheme. So use <a href="tel:555-555-5555">555-555-5555</a> and you should be good to go.

If you want to use it for an image, the <a> tag can handle the <img/> placed in it just like other normal situations with : <a href="tel:555-555-5555"><img src="path/to/phone/icon.jpg" /></a>

The proper URL scheme is tel:[number] so you would do

<a href="tel:5551234567"><img src="callme.jpg" /></a>

Want to add an answer here for the sake of completeness.

<a href="tel:1234567">Call 123-4567</a>

Works just fine on most devices. However, on desktops this will appear as a link which does nothing when you click on it so you should consider using CSS to make it conditionally visible only on mobile devices.

Also, you should know that Skype (which is fairly popular) uses a different syntax by default (but can be parametered to use tel:).

<a href="callto:1234567">Call 123-4567</a>

However, I think in latest mobile browsers (I know for sure on Android) now the tel syntax should offer a popup of available applications that can be used to complete the calling action.

Clickable smartphone link code:

The following link can be used to make a clickable phone link. You can copy the code below and paste it into your webpage, then edit with your phone number. This code may not work on all phones but does work for iPhone, Droid / Android, and Blackberry.

<a href="tel:1-847-555-5555">1-847-555-5555</a>

Phone number links can be used with the dashes, as shown above, or without them as well as in the following example:

<a href="tel:18475555555">1-847-555-5555</a>

It is also possible to use any text in the link as long as the phone number is set up with the "tel:18475555555" as in this example:

<a href="tel:18475555555">Click Here To Call Support 1-847-555-5555</a>

Below is a clickable telephone hyperlink you can check out. In most non-phone browsers this link will give you a "The webpage cannot be displayed" error or nothing will happen.

NOTE: The iPhone Safari browser will automatically detect a phone number on a page and will convert the text into a call link without using any of the code on this page.

WTAI smartphone link code: The WTAI or "Wireless Telephony Application Interface" link code is shown below. This code is considered to be the correct mobile phone protocol and will work on smartphones like Droid, however, it may not work for Apple Safari on iPhone and the above code is recommended.

<a href="wtai://wp/mc;18475555555">Click Here To Call Support 1-847-555-5555</a>