First Public Working Draft: Incremental Font Transfer via Range Request

The Web Fonts Working Group has published a First Public Working Draft of Incremental Font Transfer (IFT) via Range Request which focuses on incremental font transfer via HTTP range requests. IFT is a collection of technologies that help decrease the perceived latency between the time when a browser realizes it needs a font and when the necessary text can be rendered with that font. Without IFT, browsers need to download every last byte of a font before it can render any characters using that font. The specification describes the “Range-request method” in which the browser uses HTTP range requests to download only specific regions of the font file that it needs. This method has best performance on Chinese, Japanese, and Korean languages as these languages usually have the largest font files, and usually include many glyphs.