HTML Attributes
Attributes provide additional information about HTML elements.
HTML Attributes
- All HTML elements can have attributes
- Attributes provide additional information about an element
- Attributes are always specified in the start tag
- Attributes usually come in name/value pairs like: name="value"
The href Attribute
HTML links are defined with the
<a> tag. The link address is specified in the href attribute:Example :
<a href="http://bablooaj.blogspot.com/"><This is a link </a>
The src Attribute
HTML images are defined with the
<img> tag.
The filename of the image source is specified in the
src attribute:Example :
<img src="img_girl.jpg">
The width and height Attributes
Images in HTML have a set of size attributes, which specifies the width and height of the image:
Example :
<img src="img_girl.jpg" width="500" height="600">
The image size is specified in pixels: width="500" means 500 pixels wide.
The alt Attribute
The
alt attribute specifies an alternative text to be used, when an image cannot be displayed.
The value of the attribute can be read by screen readers. This way, someone "listening" to the webpage, e.g. a blind person, can "hear" the element.
Example :
<img src="img_girl.jpg" alt="Girl with a jacket">
The
alt attribute is also useful if the image does not exist:Example :
See what happens if we try to display an image that does not exist:
<img src="img_typo.jpg" alt="Girl with a jacket">
The style Attribute
The
style attribute is used to specify the styling of an element, like color, font, size etc.Example :
<p style="color:red">I am a paragraph</p>
The lang Attribute
The language of the document can be declared in the
<html> tag.
The language is declared with the
lang attribute.
Declaring a language is important for accessibility applications (screen readers) and search engines:
<!DOCTYPE html>
<html lang="en-US">
<body>
...
</body>
</html>
<html lang="en-US">
<body>
...
</body>
</html>
The first two letters specify the language (en). If there is a dialect, use two more letters (US).
The title Attribute
Here, a
title attribute is added to the <p> element. The value of the title attribute will be displayed as a tooltip when you mouse over the paragraph:Example :
<p title="I'm a tooltip">
This is a paragraph.
</p>
This is a paragraph.
</p>
We Suggest: Use Lowercase Attributes
The HTML5 standard does not require lowercase attribute names.
The title attribute can be written with uppercase or lowercase like title or TITLE.
Webmasteraj.com recommends lowercase in HTML, and demands lowercase for stricter document types like XHTML.
We Suggest: Quote Attribute Values
The HTML5 standard does not require quotes around attribute values.
The
href attribute, demonstrated above, can be written without quotes:Bad :
<a href=https://www.webmasteraj.com>
Good :
<a href="https://www.webmasteraj.com">
Sometimes it is necessary to use quotes. This example will not display the title attribute correctly, because it contains a space:
Example :
<p title=About Webmasteraj>
Single or Double Quotes?
Double quotes around attribute values are the most common in HTML, but single quotes can also be used.
In some situations, when the attribute value itself contains double quotes, it is necessary to use single quotes:
<p title='John "ShotGun" Nelson'>
Or vice versa:
<p title="John 'ShotGun' Nelson">
Chapter Summary
- All HTML elements can have attributes
- The
titleattribute provides additional "tool-tip" information - The
hrefattribute provides address information for links - The
widthandheightattributes provide size information for images - The
altattribute provides text for screen readers - At W3Schools we always use lowercase attribute names
- At W3Schools we always quote attribute values with double quotes
HTML Attributes
Below is an alphabetical list of some attributes often used in HTML:
| Attribute | Description |
|---|---|
| alt | Specifies an alternative text for an image, when the image cannot be displayed |
| disabled | Specifies that an input element should be disabled |
| href | Specifies the URL (web address) for a link |
| id | Specifies a unique id for an element |
| src | Specifies the URL (web address) for an image |
| style | Specifies an inline CSS style for an element |
| title | Specifies extra information about an element (displayed as a tool tip) |
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