Thursday, August 16, 2012

CSS Font

CSS font properties define the font family, boldness, size, and the style of a text.

Difference Between Serif and Sans-serif Fonts

Serif vs. Sans-serif
Remark On computer screens, sans-serif fonts are considered easier to read than serif fonts.

CSS Font Families

In CSS, there are two types of font family names:
  • generic family - a group of font families with a similar look (like "Serif" or "Monospace")
  • font family - a specific font family (like "Times New Roman" or "Arial")
Generic familyFont familyDescription
SerifTimes New Roman
Serif fonts have small lines at the ends on some characters
"Sans" means without - these fonts do not have the lines at the ends of characters
MonospaceCourier New
Lucida Console
All monospace characters have the same width

Font Family

The font family of a text is set with the font-family property.

The font-family property should hold several font names as a "fallback" system. If the browser does not support the first font, it tries the next font.

Start with the font you want, and end with a generic family, to let the browser pick a similar font in the generic family, if no other fonts are available.

Note: If the name of a font family is more than one word, it must be in quotation marks, like font-family: "Times New Roman".

More than one font family is specified in a comma-separated list:


p{font-family:"Times New Roman", Times, serif;}

Try it yourself »

For more commonly used font combinations, look at our Web Safe Font Combinations.

Font Style

The font-style property is mostly used to specify italic text.
This property has three values:
  • normal - The text is shown normally
  • italic - The text is shown in italics
  • oblique - The text is "leaning" (oblique is very similar to italic, but less supported)


p.normal {font-style:normal;}
p.italic {font-style:italic;}
p.oblique {font-style:oblique;}

Try it yourself »

Font Size

The font-size property sets the size of the text.

Being able to manage the text size is important in web design. However, you should not use font size adjustments to make paragraphs look like headings, or headings look like paragraphs.

Always use the proper HTML tags, like <h1> - <h6> for headings and <p> for paragraphs.

The font-size value can be an absolute, or relative size.
Absolute size:
  • Sets the text to a specified size
  • Does not allow a user to change the text size in all browsers (bad for accessibility reasons)
  • Absolute size is useful when the physical size of the output is known
Relative size:
  • Sets the size relative to surrounding elements
  • Allows a user to change the text size in browsers
Remark If you do not specify a font size, the default size for normal text, like paragraphs, is 16px (16px=1em).

Set Font Size With Pixels

Setting the text size with pixels gives you full control over the text size:


h1 {font-size:40px;}
h2 {font-size:30px;}
p {font-size:14px;}

Try it yourself »

The example above allows Internet Explorer 9, Firefox, Chrome, Opera, and Safari to resize the text.

Note: The example above does not work in IE, prior version 9.

The text can be resized in all browsers using the zoom tool (however, this resizes the entire page, not 
just the text).

Set Font Size With Em

To avoid the resizing problem with older versions of Internet Explorer, many developers use em instead of pixels.

The em size unit is recommended by the W3C.

1em is equal to the current font size. The default text size in browsers is 16px. So, the default size of 1em is 16px.

The size can be calculated from pixels to em using this formula: pixels/16=em


h1 {font-size:2.5em;} /* 40px/16=2.5em */
h2 {font-size:1.875em;} /* 30px/16=1.875em */
p {font-size:0.875em;} /* 14px/16=0.875em */

Try it yourself »

In the example above, the text size in em is the same as the previous example in pixels. However, with the em size, it is possible to adjust the text size in all browsers.

Unfortunately, there is still a problem with older versions of IE. The text becomes larger than it should when made larger, and smaller than it should when made smaller.

Use a Combination of Percent and Em

The solution that works in all browsers, is to set a default font-size in percent for the <body> element:


body {font-size:100%;}
h1 {font-size:2.5em;}
h2 {font-size:1.875em;}
p {font-size:0.875em;}

Try it yourself »

Our code now works great! It shows the same text size in all browsers, and allows all browsers to zoom or resize the text!

More Examples

Set the boldness of the font
This example demonstrates how to set the boldness of a font.

Set the variant of the font
This example demonstrates how to set the variant of a font.

All the font properties in one declaration
This example demonstrates how to use the shorthand property for setting all of the font properties in one declaration.

All CSS Font Properties

fontSets all the font properties in one declaration
font-familySpecifies the font family for text
font-sizeSpecifies the font size of text
font-styleSpecifies the font style for text
font-variantSpecifies whether or not a text should be displayed in a small-caps font
font-weightSpecifies the weight of a font

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