Original Image by Christian Haugen/Flickr

As we reported back when the W3C’s HTML Working Group first considered adding it to the list of HTML elements, the primary purpose of the main element is to map the WAI-ARIA landmark role “main” to an HTML element.

Thanks to the hard work of developer Steve Faulkner, who wrote up the proposal for <main> and did much of the hard work convincing the Working Group that it was worth adding to the spec, you can start using the main element today. In fact <main> is already natively supported in nightly builds of Firefox and Chrome.

There’s an ongoing debate as to whether more than one <main> element should be allowed on the page. Currently the W3C’s draft of the spec explicitly prohibits more than one <main> per page, but the WHATWG’s version of the spec is less specific.

It might sound counter-intuitive to have more than one <main> per page, but the argument is that the rest of the new block level tags have no such restrictions. In other words, there can be more than one <header>, more than one <footer> and more than one <nav> so why not more than one <main>? Developer Jeremy Keith has a post on why more than one <main> could be a good idea. [Update: There's also been some discussion on the HTML WG mailing list and a call for supporting data. As Steven Falkner notes in the comments below "the discussion continues, but at this stage there is no evidence that such a change will bring a benefit to users and may well complicate the usage of the feature and dilute its meaning and benefit for users."]

For now we suggest sticking to just one main element per page, which simplifies using <main>. Chances are you have something like <div id="main"> in your code right now. To use the new main element, just rewrite that to be <main role="main">.

The role="main" may seem redundant, and someday it will be, but right now it acts as a polyfill for older web browsers, ensuring that they map the element to accessibility APIs. Older browsers will also need to be told about the element’s block level status with main {display:block;}. HTML5 shiv, a popular way to add support for the new elements to older browsers, has already been updated to support <main>.