How do I open a .ttf 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 font format Apple and Microsoft built in 1991 — double-click to install.

Can I convert a .ttf file?

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

.ttf files

.ttf file

TrueType Font

The font format Apple and Microsoft built in 1991 — double-click to install.

What opens a .ttf 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 .ttf file is

TrueType uses quadratic curves and includes hinting instructions that keep letterforms crisp at small sizes on screen. Every operating system installs one from a double-click and a button in the preview window. Fonts are licensed software, not just files, so bundling one with a document or a website is often restricted regardless of the format.

Converting it

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

Details

Extension: .ttf
Full name: TrueType Font
Category: Fonts
MIME type: font/ttf
Created by: Apple / Microsoft
Format: Binary

Common questions

How do I open a .ttf 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 font format Apple and Microsoft built in 1991 — double-click to install.
What is a .ttf file?: TrueType Font. TrueType uses quadratic curves and includes hinting instructions that keep letterforms crisp at small sizes on screen. Every operating system installs one from a double-click and a button in the preview window.
Can I convert a .ttf file?: Yes. It is usually converted to .otf, .woff, .woff2 or .eot, either by exporting from one of the programs listed above or with a format converter.

.otf — OpenType Font The modern font format, with support for ligatures, alternates and huge characte
.woff2 — Web Open Font Format 2 The current web font format, roughly 30% smaller than WOFF.
.woff — Web Open Font Format A compressed font wrapper made for downloading into web pages.

Sources

Media Types Registry — IANA
Official vendor product documentation — At One Place

How these figures are compiled and checked