---
name: Word spacing
slug: word-spacing
category: typography
status: published
created: 2026-08-21T00:00:00.000Z
modified: 2026-08-21T00:00:00.000Z
definition: The width of the gaps between words, which justification stretches
  and which, set too wide, opens rivers down a paragraph.
aliases:
  - name: word space
  - name: interword spacing
tags:
  - spacing
relations:
  contrastWith:
    - tracking
    - kerning
    - non-breaking-space
  variantOf: []
  partOf: []
  seeAlso: []
implementations: []
sources:
  - title: Word spaces (Practical Typography)
    url: https://practicaltypography.com/
demo: inline
exhibit: false
useWhen: the gaps between words, not between letters
---

The gap between two words is a character, and like every other character in the
font it was drawn by somebody. Its width is part of the face's fit, typically
somewhere near a quarter of an em, and it is tuned against the rest of the
design: a face with tight letterfitting gets a narrower space, a wide face gets a
broader one. The CSS property named after it does not set that width, it adds to
it, which is why `word-spacing: 0.3em` means three tenths of an em on top of
whatever the designer already decided rather than a space three tenths of an em
wide.

Most of the time the value you should add is zero. The place where the gaps move
anyway is [justified text](/justified-text), which reaches both margins by
stretching the word spaces on every line until the last word lands flush, so the
narrower the [measure](/measure), the more each space has to give. Stretch them
far enough and two things happen: the paragraph's colour goes patchy, because
white space is now unevenly distributed through the grey, and gaps on
consecutive lines start falling under one another until the eye joins them into
a [river](/river). The fixes are more places to break and less to stretch:
[hyphenation](/hyphenation) gives the line breaker somewhere else to go, and a
[rag](/rag) removes the stretching entirely.

It is worth keeping separate from the space between letters. Widening the gaps
between words separates the words; widening the gaps between letters, which is
[tracking](/tracking), loosens the words themselves and can make them stop
reading as units at all. The two failures look alike from a distance and have
opposite fixes. Nearby is a much older argument about how many spaces follow a
full stop, where the answer for typeset text is one: the double space is a
monospace typewriter habit for a machine that could not vary the width of
anything, and in a proportional face it punches holes in the paragraph. Where a
space must not break at all, that is a
[non-breaking space](/non-breaking-space) rather than a spacing decision.

There is an accessibility floor under all of this. WCAG's
[text spacing](/text-spacing) criterion says a reader must be able to push word
spacing to at least 0.16em, along with the other spacing knobs, without losing
content or function, which in practice means a layout that survives being pulled
apart rather than one that was measured to the pixel. If widening the word
spaces of a paragraph clips it or hides a button, the fault is in the container,
not in the reader.