HTML width/height Attribute vs CSS width/height Property

In HTML5, the width and height attributes are supported by certain elements such as images and graphics-related tags. These attributes define the element's dimensions but can be overridden by CSS styles. 

• Supported by elements like <img>, <iframe>, <canvas>, and <svg>.
• Not supported by elements such as <div>, <span>, <article> and <section>.
• Width and height attributes provide default dimensions for supported elements.
• CSS width and height properties have higher priority and can override HTML attributes.

Example: CSS Overrides HTML Width and Height Attributes

HTML:

<!-- HTML -->
<img src="image.jpg" width="600" height="200">

CSS:

/* CSS */
img {
 width: 400px;
 height: 400px;
}

• The image will be displayed as 400px × 400px.
• The CSS width and height properties override the HTML width and height attributes.

Some attributes have a stronger effect on an element's appearance, and overriding them may require using the !important rule in CSS.

Example: Uses height/width attributes and height/width property.

Differences between HTML width/height attribute and CSS width/height property

Here are some differences: