HTML attributes can be added to the opening tag of an HTML element to change the element’s default behavior or provide additional information about the element.

They consist of a name and a value using the following syntax: name="value".

<tag name="value"></tag>

So for example, the <img> image element has a mandatory src attribute that contains the image file path/URL:

  • src is the attribute name.
  • codecademy_logo.png is the attribute value.

All HTML elements can have attributes. Multiple of them, too!


Note: Attribute names are case insensitive, but it is a good practice to keep HTML markup lowercase.

Unique ID Attributes

In HTML, specific and unique id attributes can be assigned to different elements in order to differentiate between them.

When needed, the id value can be called upon by CSS and JavaScript to manipulate, format, and perform specific instructions on that element and that element only.

Valid id attributes should begin with a letter and should only contain letters (a-Z), digits (0-9), hyphens (-), underscores (_), and periods (.).



In the provided example, we are giving the <p> paragraph element an unique identifier using the id attribute and changing the color of the default text using the style attribute:

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