Em dash vs. en dash
Last reviewed: 2026-06-21
The em dash (—) is a long punctuation mark used to set off a strong break or aside within a sentence. The en dash (–) is a shorter mark used mainly to express a range or a connection between two things. They are distinct from the hyphen (-), the shortest of the three, which joins words and parts of words.
Three different marks
The three marks differ in length and in job. The hyphen (-) is the shortest and joins: compound modifiers ("well-known"), some prefixes, and word breaks. The en dash (–), about the width of a capital N, primarily indicates a range — "pages 10–20", "Monday–Friday", "the 2015–18 season" — and connections or relationships, as in "the New York–London flight" or "a liberal–conservative debate". The em dash (—), about the width of a capital M and the longest of the three, marks a sharp break in a sentence: an interruption, an abrupt change of thought, or an emphatic aside — like this one.
Em dashes can replace commas, parentheses, or a colon to create a stronger or more informal pause. Style guides differ on spacing: many American guides (such as Chicago) set the em dash closed, with no spaces around it, while others add thin or full spaces. The en dash is normally closed up against the items it joins.
Why it matters for website copy
The dashes are easy to confuse and easy to get wrong on the web, because a standard keyboard has only the hyphen. Writers often type a single hyphen where an em dash belongs ("New York - London"), or two hyphens (--) that some editors convert to a dash and some do not. Copy pasted from word processors may arrive with the right Unicode characters, while copy typed directly into a CMS may not. The result is a site that mixes "10-20", "10–20", and "10 — 20" for the same kind of range.
Using the wrong mark is a small thing, but small typographic inconsistencies accumulate and make polished copy look unpolished. Choosing one convention — em dashes for breaks, en dashes for ranges, hyphens for compounds — and applying it consistently is a matter of punctuation and style, the kinds of surface detail a careful proofreading pass is meant to catch.
Common mistakes
The most common mistake is using a hyphen where an en or em dash belongs — "pages 10-20" instead of "10–20", or "the upside - and the risk" instead of an em dash. Another is mixing all three inconsistently across a site so the same construction is punctuated three different ways. A third is adding or removing spaces around the em dash at random; whichever spacing you choose, apply it uniformly.
Related terms & reading
More glossary terms
- Placeholder text Temporary filler copy a template ships with so a layout has something to show before the real copy is written.
- Lorem ipsum Scrambled pseudo-Latin filler used to show how a layout looks before real copy is written.
- Proofreading vs. copyediting Proofreading is the final surface check for errors; copyediting is the deeper earlier pass that improves clarity and style.
- Style consistency Treating the same writing choice the same way everywhere, so a body of text reads as one coherent voice.
- Rendered HTML (vs. source HTML) The final page a browser builds after running JavaScript — as opposed to the raw source HTML the server first sent.
- Serial (Oxford) comma The comma before the final "and" or "or" in a list of three or more items, as in "red, white, and blue".
- Smart quotes vs. straight quotes Smart quotes are the curly, directional marks of finished prose; straight quotes are the neutral typewriter marks.
- Typo A small accidental mistake in typed text — a mistyped, transposed, doubled, or dropped character or word.
- Homophone A word that sounds like another but means something different — "their" vs. "there", "your" vs. "you’re".
- Its vs. it’s "Its" is possessive ("its name"); "it’s" is short for "it is" or "it has" ("it’s ready").
- Sentence case vs. title case Sentence case capitalizes only the first word; title case capitalizes most words, as in a headline.
- Microcopy The small, functional bits of interface text — buttons, form hints, error messages, tooltips — that guide a user.
- Readability How easily a reader can understand a piece of writing — a product of sentence length, word choice, and structure.
Related reading: apply it consistently.
Frequently asked questions
What is the difference between an em dash and an en dash?
An em dash (—) is longer and sets off a break or aside within a sentence, often replacing commas, parentheses, or a colon. An en dash (–) is shorter and marks a range ("pages 10–20") or a connection ("the New York–London flight"). Both are distinct from the still-shorter hyphen (-), which joins words.
When should I use a hyphen instead of a dash?
Use a hyphen to join words and word parts — compound modifiers like "well-known", and some prefixes. Use an en dash for ranges and connections, and an em dash for sentence breaks. The three are different marks of different lengths with different jobs.