HTML <sub> Tag
<sub> tag represents subscript text in an HTML document.
Subscripts and superscripts are often used in mathematical expressions and in languages such as French as a convention to represent some abbreviations.
<sub> element should only be used to mark up typographical conventions with specific meanings. Generally, it should only be used in cases where, the absense of the element would change the meaning of the content. It should not be used solely for presentation purposes.
The same principle applies to the
<sup> tag (which represents superscript text).
<sub> tag is written as
</sub> with the subscript text inserted between the start and end tags.
Attributes can be added to an HTML element to provide more information about how the element should appear or behave.
There are 3 kinds of attributes that you can add to your HTML tags: Element-specific, global, and event handler content attributes.
<sub> element accepts the following attributes.
This table shows the attributes that are specific to the
The following attributes are standard across all HTML5 elements. Therefore, you can use these attributes with the
<sub> tag , as well as with all other HTML tags.
For a full explanation of these attributes, see HTML 5 global attributes.
Event Handler Content Attributes
Event handler content attributes enable you to invoke a script from within your HTML. The script is invoked when a certain "event" occurs. Each event handler content attribute deals with a different event.
Below are the standard HTML5 event handler content attributes.
Again, you can use any of these with the
<sub> element, as well as any other HTML5 element.
For a full explanation of these attributes, see HTML 5 event handler content attributes.
Differences Between HTML 4 & HTML 5
Here's a template for the
<sub> tag with all available attributes for the tag (based on HTML5). These are grouped into attribute types, each type separated by a space. In many cases, you will probably only need one or two (if any) attributes. Simply remove the attributes you don't need.
Here are the official specifications for the
- HTML5 Specification (W3C)
- HTML Living Standard (WHATWG)
- Current W3C Draft (the next version that is currently being worked on)
- HTML 4 (W3C)
What's the Difference?
W3C creates "snapshot" specifications that don't change once defined. So the HTML5 specification won't change once it becomes an official recommendation. WHATWG on the other hand, develops a "living standard" that is updated on a regular basis. In general, you will probably find that the HTML living standard will be more closely aligned to the current W3C draft than to the HTML5 specification.