Use standard fonts
In 2010 (Site Checker) the average weight of a web font was 2KB. In 2017, the average web font weight increased over 50 times to 113KB. When a font is pre-installed on a device, the user does not need to download it. Therefore, using a standard font reduces bandwidth usage and speeds up site loading.
There are dozens of fonts preinstalled on devices. Here is a small selection of the most popular standard fonts:
- Sans serif : Arial, Impact, Lucida Sans, Tahoma, Trebuchet MS, Verdana
- Casual : Comic Sans MS
- Serif : Georgia, Times New Roman
- Serif mono : Courier New
All of the above fonts are included on Mac OS X, Windows 7, and more.
Use WOFF2 format
Some font formats such as WOFF (most popular) and WOFF2 (most compressed) have optimized weights that reduce the weight of the font downloaded by users. Some older versions of browsers do not support the WOFF2 format.
Respect accessibility best practices
Standard fonts are also recommended for readability (as opposed to cursive, handwritten, decorative fonts, among others which might be difficult to read for people with disabilities).
Avoid using condensed fonts, long portions of text in all caps, underlined or in italics, and animated or scrolling text.