---
name: Zero-width space
slug: zero-width-space
category: typography
status: published
created: 2026-08-21T00:00:00.000Z
modified: 2026-08-21T00:00:00.000Z
definition: An invisible character that takes no width and adds a legal break
  point, letting a long string wrap without showing a hyphen.
aliases:
  - name: ZWSP
  - name: U+200B
  - name: invisible break
tags:
  - i18n
  - web-platform
relations:
  contrastWith:
    - word-break
    - non-breaking-space
    - soft-hyphen
  variantOf: []
  partOf: []
  seeAlso: []
implementations: []
sources:
  - title: Zero-width space (Wikipedia)
    url: https://en.wikipedia.org/wiki/Zero-width_space
demo: inline
exhibit: false
useWhen: breaking a long identifier with no visible mark
---

U+200B is a character with no drawing and no advance width. Its entire job is to
tell the line breaker that a wrap is allowed here, which is the one thing a long
unbroken string does not otherwise offer. Put one between the words of a camel-case
identifier, after the slashes of a URL, or inside a hash, and the string starts
wrapping at the places you chose instead of running off the side of its column.
Nothing appears at the break: no hyphen, no dash, no gap, because there is no
glyph to draw.

That silence is the difference from a [soft hyphen](/soft-hyphen), which is the
same kind of character with the opposite manners. A soft hyphen also marks a
permitted break and is also invisible until it is used, but when the line does
break there, a hyphen is drawn. That is right for prose, where a hyphen tells the
reader a word was split, and wrong for anything a reader might copy or type back:
a hyphen in the middle of `ProductCatalogSyncScheduler` reads as part of the name.
Where a break must never happen at all, the mirror image is a
[non-breaking space](/non-breaking-space), a character that occupies width and
forbids the break its ordinary twin would allow.

The alternative to placing characters by hand is asking CSS to break anywhere:
`overflow-wrap: anywhere`, or [word-break](/word-break) with `break-all`. That
needs no editing of content, and it also has no judgement, so it will split a name
mid-syllable and hyphenate nothing. A zero-width space is the opposite trade: you
say where the seams are, once, and every line thereafter breaks somewhere a reader
would have chosen. For generated strings, inserting one after each separator is a
one-line transform.

The cost is that the character is really there. It survives copy and paste, so a
pasted identifier can carry invisible characters into a code editor, a search
field, or a database, where it will not match the string it looks identical to.
It counts toward a length limit, it can break an exact-match query, and it is a
known trick for slipping past naive text filters. Use it in text you are rendering
for reading, strip it from anything you are storing or comparing, and prefer the
CSS route wherever the content is not yours to edit.