HTML Images
Images can improve the design and the appearance of a web page.
HTML Images Syntax
In HTML, images are defined with the <img>
tag.
The <img>
tag is empty, it contains attributes only, and does not
have a closing tag.
The src
attribute specifies the URL
(web address) of the image:
<img src="url">
The alt Attribute
The alt
attribute provides an alternate text for an image, if the user for
some reason cannot view it (because of slow connection, an error in the src
attribute, or if the user uses a screen reader).
The value of the alt
attribute should describe the image:
If a browser cannot find an image, it will display the value of the alt
attribute:
Note: The alt
attribute is required. A web page will not validate correctly without it.
Image Size - Width and Height
You can use the style
attribute to specify the width and
height of an image.
Example
<img src="img_girl.jpg" alt="Girl in a jacket" style="width:500px;height:600px;">
Try it Yourself »
Alternatively, you can use the width
and height
attributes:
The width
and height
attributes always defines the width and height of the
image in pixels.
Note: Always specify the width and height of an image. If width and height are not specified, the page might flicker while the image loads.
Width and Height, or Style?
The width
, height
, and style
attributes are valid in HTML.
However, we suggest using the style
attribute. It prevents styles sheets from changing
the size of images:
Example
<!DOCTYPE html>
<html>
<head>
<style>
img {
width: 100%;
}
</style>
</head>
<body>
<img src="html5.gif" alt="HTML5 Icon" width="128" height="128">
<img src="html5.gif" alt="HTML5 Icon" style="width:128px;height:128px;">
</body>
</html>
Try it Yourself »
Images in Another Folder
If not specified, the browser expects to find the image in the same folder as the web page.
However, it is common to store images in a sub-folder. You must then include the folder
name in the src
attribute:
Example
<img src="/images/html5.gif"
alt="HTML5 Icon" style="width:128px;height:128px;">
Try it Yourself »
Images on Another Server
Some web sites store their images on image servers.
Actually, you can access images from any web address in the world:
Example
<img src="https://www.w3schools.com/images/w3schools_green.jpg" alt="W3Schools.com">
Try it Yourself »
You can read more about file paths in the chapter HTML File Paths.
Animated Images
HTML allows animated GIFs:
Example
<img src="programming.gif" alt="Computer Man" style="width:48px;height:48px;">
Try it Yourself »
Image as a Link
To use an image as a link, put the <img>
tag inside the <a>
tag:
Example
<a href="default.asp">
<img src="smiley.gif" alt="HTML tutorial"
style="width:42px;height:42px;border:0;">
</a>
Try it Yourself »
Note: border:0;
is added to prevent IE9 (and earlier) from displaying a border around the image
(when the image is a link).
Image Floating
Use the CSS float
property to let the image float to the right or to the left of a text:
Example
<p><img src="smiley.gif" alt="Smiley face"
style="float:right;width:42px;height:42px;">
The image will float to the right of
the text.</p>
<p><img src="smiley.gif" alt="Smiley face"
style="float:left;width:42px;height:42px;">
The image will float to the left of
the text.</p>
Try it Yourself »
Tip: To learn more about CSS Float, read our CSS Float Tutorial.
HTML Screen Readers
A screen reader is a software program that reads the HTML code, converts the text, and allows the user to "listen" to the content. Screen readers are useful for people who are visually impaired or learning disabled.
Chapter Summary
- Use the HTML
<img>
element to define an image - Use the HTML
src
attribute to define the URL of the image - Use the HTML
alt
attribute to define an alternate text for an image, if it cannot be displayed - Use the HTML
width
andheight
attributes to define the size of the image - Use the CSS
width
andheight
properties to define the size of the image (alternatively) - Use the CSS
float
property to let the image float
Loading images takes time. Large images can slow down your page. Use images carefully.
HTML Exercises
HTML Image Tags
Tag | Description |
---|---|
<img> | Defines an image |
<map> | Defines an image-map |
<area> | Defines a clickable area inside an image-map |
<picture> | Defines a container for multiple image resources |
For a complete list of all available HTML tags, visit our HTML Tag Reference.