How to detect support for the HTML5 “download” attribute?

Question

One of the new features implemented in HTML5 is the download attribute for anchor tags. The benefit of this attribute is that it gives users the means to downlo

Answer 1

Use the Modernizr approach: create the element, and check if the attribute is defined:

var a = document.createElement('a');
if (typeof a.download != "undefined") {
    alert('has support');
}

Answer 2

A single-line if condition to keep things simplified:

if (document.createElement('a').download==undefined && e.target.hasAttribute('download'))
{
 e.preventDefault();
 console.log('Error: this is a download link, please right-click to save the file.');
}

Support for the download attribute is spotty (Chrome 14+, Firefox 20+, IE13+, Safari 10+ and no support in (real) Opera. The script above will not interfere with supported browsers.