---
name: Ligature
slug: ligature
category: typography
status: published
created: 2026-08-21T00:00:00.000Z
modified: 2026-08-21T00:00:00.000Z
definition: A single glyph that replaces two or more letters whose shapes would
  otherwise collide, such as the f and i pair.
aliases:
  - name: ligatures
  - name: standard ligatures
    source: opentype
  - name: discretionary ligatures
    source: opentype
  - name: liga
    source: opentype
  - name: programming ligatures
    source: community
tags:
  - fonts
relations:
  contrastWith:
    - icon-font
    - contextual-alternates
    - opentype-features
    - kerning
  variantOf: []
  partOf: []
  seeAlso: []
implementations: []
sources:
  - title: "Practical Typography: Ligatures"
    url: https://practicaltypography.com/
  - title: "MDN: OpenType font features"
    url: https://developer.mozilla.org/en-US/docs/Web/CSS/Guides/Fonts/OpenType_fonts
demo: inline
exhibit: false
useWhen: two letters collide and the font fuses them
---

Some letters do not get along. In many serif faces the arm of an f reaches far
enough to crash into the dot of a following i, and the pair renders as a smudge
at small sizes and as an obvious accident at large ones. The typographic answer
is older than printing presses: draw the two letters as one glyph, shaped so the
collision never happens. That glyph is a ligature.

The f family is where most of them live, since f is the letter with the longest
reach: fi, fl, ff, ffi and ffl are the standard set. Which of them a given
typeface carries is entirely up to its designer, and a face whose f is drawn
with a short arm may need none at all. Beyond the standard set sit discretionary
ligatures, the decorative ones (st, ct, and similar), which exist to be turned
on deliberately rather than to solve a problem.

The distinction is exactly how the OpenType features are named. `liga` holds the
standard ligatures and browsers apply it by default to body text;
`dlig` holds the discretionary ones and is off until asked for; `clig` covers
contextual cases. CSS reaches all of them through `font-variant-ligatures`,
where `none` switches the lot off. Off is occasionally the right answer: at very
wide [tracking](/tracking) a fused pair looks wrong beside letters that have
been pushed apart, and text being revealed or animated one character at a time
cannot afford a glyph that spans two of them.

Programming ligatures are a separate idea wearing the same word. Faces like Fira
Code and JetBrains Mono use the mechanism to render `=>` as a single arrow and
`!=` as a not-equal sign, which is a substitution for meaning rather than for
collision, and one that some readers like as much as others dislike. Note what
this specimen's own typeface does: it fuses ff, ffi and ffl, and leaves the
classic fi pair alone, which is a good reminder that the feature is a promise
the font makes, not one the browser can keep on its behalf.