HTML5 - Attributes

As explained in the previous chapter, elements may contain attributes that are used to set various properties of an element.

Some attributes are defined globally and can be used on any element, while others are defined for specific elements only. All attributes have a name and a value and look like as shown below in the example.

Following is the example of an HTML5 attributes which illustrates how to mark up a div element with an attribute named class using a value of "example" −

<div class = "example">...</div>

Attributes may only be specified within start tags and must never be used in end tags.

HTML5 attributes are case insensitive and may be written in all uppercase or mixed case, although the most common convention is to stick with lowercase.

Standard Attributes

The attributes listed below are supported by almost all the HTML 5 tags.

Attribute Options Function
accesskey User Defined Specifies a keyboard shortcut to access an element.
align right, left, center Horizontally aligns tags
background URL Places an background image behind an element
bgcolor numeric, hexidecimal, RGB values Places a background color behind an element
class User Defined Classifies an element for use with Cascading Style Sheets.
contenteditable true, false Specifies if the user can edit the element's content or not.
contextmenu Menu id Specifies the context menu for an element.
data-XXXX User Defined Custom attributes. Authors of a HTML document can define their own attributes. Must start with "data-".
draggable true,false, auto Specifies whether or not a user is allowed to drag an element.
height Numeric Value Specifies the height of tables, images, or table cells.
hidden hidden Specifies whether element should be visible or not.
id User Defined Names an element for use with Cascading Style Sheets.
item List of elements Used to group elements.
itemprop List of items Used to group items.
spellcheck true, false Specifies if the element must have it's spelling or grammar checked.
style CSS Style sheet Specifies an inline style for an element.
subject User define id Specifies the element's corresponding item.
tabindex Tab number Specifies the tab order of an element.
title User Defined "Pop-up" title for your elements.
valign top, middle, bottom Vertically aligns tags within an HTML element.
width Numeric Value Specifies the width of tables, images, or table cells.

For a complete list of HTML5 Tags and related attributes, please check our reference to HTML5 Tags.

Custom Attributes

A new feature being introduced in HTML 5 is the addition of custom data attributes.

A custom data attribute starts with data- and would be named based on your requirement. Here is a simple example −

<div class = "example" data-subject = "physics" data-level = "complex">

The above code will be perfectly valid HTML5 with two custom attributes called datasubject and data-level. You would be able to get the values of these attributes using JavaScript APIs or CSS in similar way as you get for standard attributes.