Web typography

Web-safe fonts are computer fonts that may reasonably be expected to be present on a wide range of computer systems, and used by Web content authors to increase the likelihood that content displays in their chosen font. If a visitor to a Web site does not have the specified font, their browser tries to select a similar alternative, based on the author-specified fallback fonts and generic families or it uses font substitution defined in the visitor's operating system.

Since being released under Microsoft's Core fonts for the Web program, Arial, Georgia, and Verdana have become three de facto fonts of the Web.

To ensure that all Web users had a basic set of fonts, Microsoft started the Core fonts for the Web initiative in 1996 (terminated in 2002). Released fonts include Arial, Courier New, Times New Roman, Comic Sans, Impact, Georgia, Trebuchet, Webdings and Verdana—under an EULA that made them freely distributable but also limited some rights to their use. Their high penetration rate has made them a staple for Web designers. However, most Linux distributions don't include these fonts by default.

CSS2 attempted to increase the tools available to Web developers by adding font synthesis, improved font matching and the ability to download remote fonts.[3]

Some CSS2 font properties were removed from CSS2.1 and later included in CSS3.[4][5]

The CSS specification allows for multiple fonts to be listed as fallback fonts.[6] In CSS, the font-family property accepts a list of comma-separated font faces to use, like so:

font-family: "Nimbus Sans L", Helvetica, Arial, sans-serif;

The first font specified is the preferred font. If this font is not available, the Web browser attempts to use the next font in the list. If none of the fonts specified are found, the browser displays its default font. This same process also happens on a per-character basis if the browser tries to display a character not present in the specified font.

To give Web designers some control over the appearance of fonts on their Web pages, even when the specified fonts are not available, the CSS specification allows the use of several generic font families. These families are designed to split fonts into several categories based on their general appearance. They are commonly specified as the last in a series of fallback fonts, as a last resort in the event that none of the fonts specified by the author are available. For several years, there were five generic families:[6]

Sans-serif

Fonts that do not have decorative markings, or serifs, on their letters. These fonts are often considered easier to read on screens.[7]

Serif

Fonts that have decorative markings, or serifs, present on their characters. These fonts are traditionally used in printed books.

Monospace

Fonts in which all characters are equally wide.

Cursive

Fonts that resemble cursive writing. These fonts may have a decorative appearance, but they can be difficult to read at small sizes, so they are generally used sparingly.

Fantasy

Fonts that may contain symbols or other decorative properties, but still represent the specified character.

[8] System-ui

Default fonts on a given system: the purpose of this option is to allow web content to integrate with the look and feel of the native OS.

ui-serif

Default fonts on a given system in a serif style

ui-sans-serif

Default fonts on a given system in a sans-serif style

ui-monospace

Default fonts on a given system in a monospace style

ui-rounded

Default fonts on a given system in a rounded style

Emoji

Fonts using emoji

Math

Fonts for complex mathematical formula and expressions.

Fangsong (Chinese: 仿宋体)

Chinese typefaces that are between serif Song and cursive Kai forms. This style is often used for government documents.

A technique to refer to and automatically download remote fonts was first specified in the CSS2 specification, which introduced the @font-face construct. At the time, fetching font files from the web was controversial because fonts meant to be used only for certain web pages could also be downloaded and installed in breach of the font license.[9]

Microsoft first added support for downloadable EOT fonts in Internet Explorer 4 in 1997. Authors had to use the proprietary WEFT tool to create a subsetted font file for each page. EOT showed that webfonts could work and the format saw some use in writing systems not supported by common operating systems. However, the format never gained widespread acceptance and was ultimately rejected by W3C.[10]

In 2006, Håkon Wium Lie started a campaign against using EOT and rather have web browsers support commonly used font formats.[11][12][13] Support for the commonly used TrueType and OpenType font formats has since been implemented in Safari 3.1, Opera 10, Mozilla Firefox 3.5 and Internet Explorer 9.

In 2010, the WOFF compression method for TrueType and OpenType fonts was submitted to W3C by the Mozilla Foundation, Opera Software and Microsoft, and browsers have since added support.[14][15][16]

Google Fonts was launched in 2010 to serve webfonts under open-source licenses. By 2016, more than 800 webfont families are available.[17]

Webfonts have become an important tool for web designers and as of 2016 a majority of sites use webfonts.[18]

By using a specific CSS @font-face embedding technique[19] it is possible to embed fonts such that they work with IE4+, Firefox 3.5+, Safari 3.1+, Opera 10+ and Chrome 4.0+. This allows the vast majority of Web users to access this functionality. Some commercial foundries object to the redistribution of their fonts. For example, Hoefler & Frere-Jones says that, while they "...enthusiastically [support] the emergence of a more expressive Web in which designers can safely and reliably use high-quality fonts online," the current delivery of fonts using @font-face is considered "illegal distribution" by the foundry and is not permitted.[20] Instead, Hoefler & Co. offer a proprietary font delivery system rooted in the cloud. Many other commercial type foundries address the redistribution of their fonts by offering a specific license, known as a web font license, which permits the use of the font software to display content on the web, a use normally prohibited by basic desktop licenses. Naturally this does not interfere with fonts and foundries under free licences.[m 1]

TrueDoc, while not specifically a webfont specification, was the first standard for embedding fonts. It was developed by the type foundry Bitstream in 1994, and became natively supported in Netscape Navigator 4, in 1996. Due to open source license restrictions, with Netscape unable to release Bitstream's source code, native support for the technology ended when Netscape Navigator 6 was released. An ActiveX plugin was available to add support for TrueDoc to Internet Explorer, but the technology had to compete against Microsoft's Embedded OpenType fonts, which had natively supported in their Internet Explorer browser since version 4.0.[21] Another impediment was the lack of open-source or free tool to create webfonts in TrueDoc format, whereas Microsoft made available a free Web Embedding Fonts Tool to create webfonts in their format.

Internet Explorer has supported font embedding through the proprietary Embedded OpenType standard since version 4.0. It uses digital rights management techniques to help prevent fonts from being copied and used without a license. A simplified subset of EOT has been formalized under the name of CWT (Compatibility Web Type, formerly EOT-Lite)[22]

Web typography applies to SVG in two ways:

1. All versions of the SVG 1.1 specification, including the SVGT subset, define a font module allowing the creation of fonts within an SVG document. Safari introduced support for many of these properties in version 3. Opera added preliminary support in version 8.0, with support for more properties in 9.0.
2. The SVG specification lets CSS apply to SVG documents in a similar manner to HTML documents, and the @font-face rule can be applied to text in SVG documents. Opera added support for this in version 10,[23] and WebKit since version 325 also supports this method using SVG fonts only.

SVG fonts was a W3C standard of fonts using SVG graphic that became a subset of OpenType fonts.[24] It allowed multicolor[25] or animated fonts.[26] It was first a subset of SVG 1.1 specifications[27] but it has been deprecated[28] in the SVG 2.0 specification. The SVG fonts as independent format is supported by most browsers apart from IE and Firefox, and is deprecated in Chrome (and Chromium).[29] That's now generally deprecated; the standard that most browser vendor agreed with is SVG font subset included in OpenType (and then WOFF superset, see below), called SVGOpenTypeFonts.[30] Firefox has supported SVG OpenType since Firefox 26.

Linking to industry-standard TrueType (TTF) and OpenType (TTF/OTF) fonts is supported by Mozilla Firefox 3.5+, Opera 10+,[31] Safari 3.1+,[32] and Google Chrome 4.0+.[33] Internet Explorer 9+ supports only those fonts with embedding permissions set to installable.[34]

The Web Open Font Format (WOFF) is essentially OpenType or TrueType with compression and additional metadata. WOFF is supported by Mozilla Firefox 3.6+,[35] Google Chrome 5+,[36][37] Opera Presto,[38] and is supported by Internet Explorer 9 (since March 14, 2011).[39] Support is available on Mac OS X Lion's Safari from release 5.1.