HTML Images
HTML Image Tags
Tag Description
<img> Defines an
image
<map> Defines
an image-map
<area> Defines
a clickable area inside an image-map
JPG Images
GIF Images
PNG Images
Example
<!DOCTYPE html>
<html>
<body>
<h2>Spectacular Mountain</h2>
<img src="pic_mountain.jpg"
alt="Mountain View" style="width:304px;height:228px;">
</body>
</html>
»
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"
alt="some_text" style="width:width;height:height;">
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).
If a browser cannot find an image, it will display the value
of the alt attribute:
Example
<img src="wrongname.gif"
alt="HTML5 Icon" style="width:128px;height:128px;">
»
The alt attribute is required. A web page will not validate
correctly without it.
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 blind, visually impaired,
or learning disabled.
Image Size - Width and Height
You can use the style attribute to specify the width and
height of an image.
The values are specified in pixels (use px after the value):
Example
<img src="html5.gif"
alt="HTML5 Icon" style="width:128px;height:128px;">
»
Alternatively, you can use the width and height attributes.
Here, the values are specified in pixels by default:
Example
<img src="html5.gif"
alt="HTML5 Icon" width="128" height="128">
»
Note: Always specify the width and height of an image. If
width and height are not specified, the page will flicker while the image
loads.
Width and Height, or Style?
Both the width, height, and style attributes are valid in
HTML5.
However, we suggest using the style attribute. It prevents
internal or external styles sheets from changing the original size of images:
Example
<!DOCTYPE html>
<html>
<head>
<style>
img {
width:100%;
}
</style>
</head>
<body>
<img src="html5.gif"
alt="HTML5 Icon" style="width:128px;height:128px;">
<img src="html5.gif"
alt="HTML5 Icon" width="128" height="128">
</body>
</html>
»
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;">
»
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.Omegas.com/images/Omegas_green.jpg" alt="Omegas.com">
»
You can read more about file paths in the chapter HTML File
Paths.
Animated Images
The GIF standard allows animated images:
Example
<img src="programming.gif"
alt="Computer Man" style="width:48px;height:48px;">
»
Note that the syntax of inserting animated images is no
different from non-animated images.
Using an Image as a Link
To use an image as a
link, simply nest the <img> tag inside the <a> tag:
Example
<a href="default.html">
<img
src="smiley.gif" alt="HTML tutorial" style="width:42px;height:42px;border:0;">
</a>
»
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>
»
Image Maps
Use the <map> tag to define an image-map. An image-map
is an image with clickable areas.
The name attribute of the <map> tag is associated with
the <img>'s usemap attribute and creates a relationship between the image
and the map.
The <map> tag contains a number of <area> tags,
that defines the clickable areas in the image-map:
Example
<img src="planets.gif"
alt="Planets" usemap="#planetmap"
style="width:145px;height:126px;">
<map name="planetmap">
<area shape="rect" coords="0,0,82,126"
alt="Sun" href="sun.htm">
<area shape="circle" coords="90,58,3"
alt="Mercury" href="mercur.htm">
<area shape="circle" coords="124,58,8"
alt="Venus" href="venus.htm
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