What is an OTF file?
OTF is a font file with more room in it: extra characters, alternate letter shapes, proper ligatures and support for languages that need letters to join up. It installs on any computer exactly like a TTF. You can convert OTF files here, both into the format and out of it.
Specification
| Full name | OpenType Font |
|---|---|
| Extensions | .otf |
| Media type | font/otf |
| Compression | Uncompressed |
| Transparency | — |
| Animation | — |
| Multiple pages | — |
| Colour depth | CFF cubic or TrueType quadratic outlines, GSUB and GPOS layout tables |
| Size limits | 65535 glyphs, up to 65535 Unicode planes via cmap format 12 |
| Introduced | 1996 |
| Developed by | Microsoft and Adobe |
| Standard | Open |
| Browser support | Every browser, including older ones |
What OTF is used for
- Professional typefaces with small caps, ligatures and alternate figures
- Multi-script typesetting for Arabic, Devanagari and other complex scripts
- Variable fonts that carry weight and width axes in one file
- Print and editorial design where OpenType features are part of the type
Strengths and limitations
What OTF does well
- Rich layout tables enable real typographic features, not just glyphs
- Compact, and closer to the way type designers draw the letters
- A single file works identically on Windows, macOS and Linux
Where OTF falls short
- Also uncompressed, so it is a poor choice for delivery over the web
- Many applications expose only a fraction of its layout features
- Can render a little less crisply than TTF on low resolution screens
Convert OTF to
Every target this format can be written out as, each on its own page.
Convert to OTF
Everything that can be turned into a OTF file.
Questions about OTF
What is a .otf file?
OTF is a font file with more room in it: extra characters, alternate letter shapes, proper ligatures and support for languages that need letters to join up. The extension .otf identifies it, and its media type is font/otf.
How do I open an OTF file?
Any current browser will open it directly, so dragging the file into a tab is usually enough. Most operating systems also preview it without extra software.
Is OTF lossy or lossless?
Uncompressed. Nothing is discarded, so repeated saves never degrade the contents.
What is OTF good for?
Rich layout tables enable real typographic features, not just glyphs. Compact, and closer to the way type designers draw the letters. A single file works identically on Windows, macOS and Linux. In practice that makes it a good fit for professional typefaces with small caps, ligatures and alternate figures, and Multi-script typesetting for Arabic, Devanagari and other complex scripts.
What are the drawbacks of OTF?
Also uncompressed, so it is a poor choice for delivery over the web. Many applications expose only a fraction of its layout features. Can render a little less crisply than TTF on low resolution screens.