OTF

OTF — OpenType Font

OTF (OpenType Font) is the modern professional font format used by virtually every type foundry shipping new typefaces today. Built on top of the TrueType container and jointly developed by Adobe and Microsoft, OTF supports advanced typographic features — ligatures, stylistic sets, small caps, contextual alternates, multiple language scripts — that older formats could not express. Every modern operating system, design tool, and browser understands OTF natively, which is why it has become the default master format for new typeface releases.

History

Adobe and Microsoft announced OpenType in 1996 as a unified successor to the rival TrueType and PostScript Type 1 standards. The first widely distributed OpenType fonts shipped in 2000 alongside Adobe's Open Source font program. Critically, OTF lifted the encoding ceiling to full Unicode and added the powerful GSUB and GPOS layout tables that let a single font express different glyph variants for different writing contexts. By the late 2000s every major foundry — Adobe, Hoefler & Co, Monotype, Linotype, FontShop — had migrated their libraries to OpenType. Today OTF is the format the typography industry actually designs for; downstream formats such as .woff, .woff2, and .ttf are usually exports of an OpenType master file. One notable wrinkle: although OpenType is officially typeface-neutral, in practice OTF files almost always carry cubic Bézier outlines in a CFF table, while TTF files carry quadratic Bézier outlines in a glyf table — the same container, but two different geometry conventions that every font tool has to handle separately.

When to use OTF

Convert OTF to other formats

Convert other formats to OTF

Frequently asked questions

What can OTF do that TTF cannot?

Technically both formats share the same container, so they have the same theoretical capabilities. In practice OTF files ship with the full OpenType feature set enabled — small caps, ligatures, stylistic alternates, fractions, ordinals, contextual swashes — while TTF files usually do not. OTF is also the format type designers actually master in.

Can I use OTF on the web?

Yes, via @font-face — but you should convert it to WOFF2 first. WOFF2 wraps the same OTF data in a Brotli-compressed envelope that ships roughly 70 percent fewer bytes, with no visual difference.

How do I convert OTF to TTF?

Use our online converter — upload your .otf file and pick TTF as the target. The glyph outlines transfer cleanly, though some OpenType advanced features may flatten because target software often does not honour them under the TTF flavour.