OpenType Font — OpenType font format with advanced typography features.
Quick facts
What is .otf
A .otf file is a OpenType Font — OpenType font format with advanced typography features.
In the mime-db registry it maps to font/otf, and it is marked as compressible. When serving .otf over HTTP, set the Content-Type header as shown in Developer info below.
Related entities: it maps to font/otf — and is delivered over HTTP via the Content-Type header.
How to open .otf files
Developer info
When served over HTTP, responses should set the following header:
Content-Type: font/otf
Common software that reads/writes .otf:
Relation chain
Related extensions
Related MIME types
Common uses
How to edit .otf files
How to create .otf files
Frequently asked questions
Common options include Font Book, FontForge. You can also open many of these files with built-in viewers or a browser.
Create a new file in any text editor or the app that owns the format and save it with the .otf extension.
font/otf is the media type identifier used for .otf files during network transfer (for example in the HTTP Content-Type header).
Sources & standards
Updated 2026-08-18
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