---
title: ".otf file — what it is and how to open it"
description: "A .otf file is an OpenType Font. The modern font format, with support for ligatures, alternates and huge character sets. How to open one on Windows, macOS and Linux, and what to convert it to."
url: https://atoneplace.net/file/otf/
site: "At One Place"
---

# .otf files

**.otf file: OpenType Font**

The modern font format, with support for ligatures, alternates and huge character sets.

## What opens a .otf file

- **Windows:** Windows Font Viewer (built in — double-click, then Install), FontForge
- **macOS:** Font Book (built in), FontForge
- **Linux:** Fonts / GNOME Font Viewer (built in), Font Manager, FontForge

## What a .otf file is

OpenType was developed jointly by Adobe and Microsoft and is now an ISO standard. It can carry TrueType or PostScript outlines and adds advanced typographic features — small caps, real ligatures, stylistic sets — that professional typefaces rely on. Installation is identical to TrueType: double-click and confirm.

## Converting it

A .otf file is commonly converted to .ttf, .woff or .woff2. It is a binary format, so a text editor will show unreadable characters rather than its contents.

## Details

- **Extension:** .otf
- **Full name:** OpenType Font
- **Category:** Fonts
- **MIME type:** font/otf
- **Created by:** Adobe / Microsoft
- **Format:** Binary

## Common questions

### How do I open a .otf file?

On Windows use Windows Font Viewer (built in — double-click, then Install); on macOS use Font Book (built in); on Linux use Fonts / GNOME Font Viewer (built in). The modern font format, with support for ligatures, alternates and huge character sets.

### What is a .otf file?

OpenType Font. OpenType was developed jointly by Adobe and Microsoft and is now an ISO standard. It can carry TrueType or PostScript outlines and adds advanced typographic features — small caps, real ligatures, stylistic sets — that professional typefaces rely on.

### Can I convert a .otf file?

Yes. It is usually converted to .ttf, .woff or .woff2, either by exporting from one of the programs listed above or with a format converter.

## Related pages

- [.ttf — TrueType Font](https://atoneplace.net/file/ttf/)
- [.woff2 — Web Open Font Format 2](https://atoneplace.net/file/woff2/)
- [.woff — Web Open Font Format](https://atoneplace.net/file/woff/)

## Sources

- Media Types Registry — IANA (https://www.iana.org/assignments/media-types/)
- Official vendor product documentation — At One Place (/about/)