Long Dash (Em Dash)

The long dash (—), better known as the em dash or em rule, is a punctuation mark consisting of a long horizontal line. It is wider than the en dash (–) and the hyphen (-) and sits at the same height as other punctuation. In running text it marks a strong break in a sentence, sets off an explanatory aside similar to parentheses, or signals an interruption in speech.

The name comes from typography: the em dash is exactly one em wide, a unit that equals the current font size. In 9-point type the em dash is 9 points wide, and in 24-point type it is 24 points wide. The en dash, by comparison, is usually half an em wide or roughly the width of an uppercase N.

In technical terms, the em dash is encoded as Unicode U+2014 (decimal 8212) and written in HTML as —. Printer's slang also calls it the mutton dash. It regularly stands in for parentheses, colons, and commas, and modern word processors can insert it automatically, but the fastest way to type it is a keyboard shortcut. See Typing the Em Dash below.

The dash has a long print history. In Ellipsis in English Literature: Signs of Omission, Anne Toner traces the earliest dash found in printed English to a letter from 1580, and the first dash in English drama to a 1588 translation of Terence's Andria by Maurice Kyffin, printed by Thomas East. In that edition the dash is literally a line of hyphens: on three occasions a series of hyphens marks an incomplete utterance, twice when one character is interrupted by another and once when the speaker interrupts himself. The printer varied the number of hyphens depending on the surrounding punctuation.

The mark caught on quickly in drama: Kyffin's 1588 translation contained three dashes, while the 1627 translation of the same play had 29. Dashes appear throughout the plays of William Shakespeare and Ben Jonson. In the first folio edition of Henry IV, Part 1, Toner writes, Hotspur dies on a dash, his last words cut short. Early 17th-century plays printed by Nicholas Okes show dashes marking a thinking pause, interruption, mid-speech realization, or change of subject, sometimes as a single long mark (⸺) as in the 1619 King Lear reprint and sometimes as hyphens (---) as in the 1622 Othello, and often preceded by a comma, colon, or semicolon.

Not everyone admired the dash. In the 18th century, Jonathan Swift rhymed "dash" with "printed trash" in On Poetry, and Henry Fielding named an unlikeable character "Dash" in his 1730 play The Author's Farce. Toner observes that in expensive folio editions the single cast rule was the prestige mark above a series of hyphens, and that one mark rather than several was both more faithful to handwriting and easier for a compositor to set. The hyphen-built dash faded with time and returned only with typewriter conventions.

The long dash is one member of a family of horizontal marks that differ in width, Unicode code point, and job. Knowing them apart prevents the most common dash mistakes.

Name	Glyph	Unicode	Typical Use
Hyphen	-	U+2010	Joins compound words and splits words across lines
Figure dash	‒	U+2012	Same width as a digit; used in phone numbers and aligned numerals
En dash	–	U+2013	Shows ranges and spans: 1754–1763, US–Canada border
Em dash	—	U+2014	Marks sentence breaks, parenthetical asides, and interruptions
Horizontal bar	―	U+2015	Introduces quoted text (quotation dash)
Swung dash	⁓	U+2053	Marks alternatives or approximates, as in dictionaries

The usual conventions for printed English are these: an unspaced em dash or a spaced en dash marks a break in a sentence, and a pair sets off a parenthetical phrase; an en dash, but not an em dash, indicates spans and ranges; an em dash or horizontal bar, but not an en dash, sets off the source of a quotation. In informal contexts a single hyphen often stands in for the en dash and a double hyphen (--) for the long dash, because both are easy to reach on a keyboard. See the full guide on Wikipedia's dash article.

The em dash does the work of parentheses, colons, commas, and semicolons, usually with more force. It is primarily used where a set of parentheses or a colon might otherwise appear, and it can also show an abrupt change of thought, an interruption in speech, or a place where a period is too strong and a comma is too weak.

Colon-Like Use

A single em dash can replace a colon to introduce an explanation, definition, or list, and it can also invert the colon's function by leading with the list.

With a Colon	With an Em Dash
Three alkali metals are the usual substituents: sodium, potassium, and lithium.	Three alkali metals are the usual substituents—sodium, potassium, and lithium.
These are the colors of the flag: red, white, and blue.	Red, white, and blue—these are the colors of the flag.

Parenthesis-Like Use

A pair of em dashes sets off a parenthetical phrase. The dashes make the aside more emphatic than commas and more noticeable than parentheses, which recede into the background.

Punctuation	Example
Commas	The food, which was delicious, reminded me of home.
Em dashes	The food—which was delicious—reminded me of home.
Parentheses	The food (which was delicious) reminded me of home.
Em dashes	Three alkali metals—sodium, potassium, and lithium—are the usual substituents.
Parentheses	Three alkali metals (sodium, potassium, and lithium) are the usual substituents.

Interruptions in Speech

A single em dash shows a speaker being cut off or breaking off mid-thought, and a pair can frame a dramatic self-interruption. This use goes back to the earliest printed drama.

Situation	Example
Cut off by another speaker	"But I'm trying to explain that I—" / "I'm aware of your mitigating circumstances, but your negative attitude was excessive."
Dramatic self-interruption	"It's gonna be legen—wait for it—dary!" (How I Met Your Mother)
Emotional trailing off	"I sense something; a presence I've not felt since—" (Star Wars: Episode IV - A New Hope)

Quotation and Attribution

An em dash (or the horizontal bar ―) can introduce quoted text or identify the source of a quotation. In some styles it replaces quotation marks entirely in dialogue, a preference of authors such as James Joyce.

Use	Example
Attributing a quote	"Seven social sins: politics without principles, wealth without work, pleasure without conscience, knowledge without character, commerce without morality, science without humanity, and worship without sacrifice." — Mahatma Gandhi
Dialogue without quotation marks	—O saints above! miss Douce said, sighed above her jumping rose. I wished I hadn't laughed so much. I feel all wet. (James Joyce, Ulysses)

Redaction

Em dashes replace censored or omitted letters, often doubled, and three em dashes (———) can stand for a completely missing word.

Use	Example
Censored name	It was alleged that D—— had been threatened with blackmail.
Missing word	He claimed it was ——— that made him leave. (three em dashes)

Itemization and Repetition

Either the en dash or the em dash can serve as a bullet at the start of list items, though a plain hyphen is more common. In bibliographies and footnotes, three em dashes one after another indicate repetition of the same author's name as the previous entry, similar to the Latin "id."

The most visible debate around the em dash is spacing. Most American style guides set it closed, meaning no spaces on either side, while several newspapers and wire services set it open, with spaces or hair spaces (U+200A) around it.

Guide	Region	Em Dash Style
The Chicago Manual of Style	US	Closed (unspaced)
APA Publication Manual	US	Closed (unspaced)
AP Stylebook	US	Open (spaced or hair spaces)
New York Times Manual of Style and Usage	US	Open (spaced)
Oxford Guide to Style (Oxford University Press)	UK	Closed (unspaced)
Penguin, Cambridge University Press, Routledge	UK	Spaced en dash instead
The Canadian Style, Editing Canadian English	Canada	Closed between words and numerals
Australian Style Manual	Australia	Closed; 2-em rule for speech breaks

The unspaced em dash has a technical quirk in justified text: it disables the flexible word spacing between the words it falls between, which can produce uneven gaps. Typesetters mitigate this with thin spaces, hair spaces, or zero-width spaces on either side. A spaced em dash or a spaced en dash avoids the problem entirely, which is one reason several UK publishers prefer the spaced en dash. The Canadian typographer Robert Bringhurst goes further in The Elements of Typographic Style, calling the em dash's length and visual magnitude "the padded and corseted aesthetic of Victorian typography" and recommending the spaced en dash.

The three most common horizontal marks form a scale: the hyphen (-) is shortest, the en dash (–) is medium, and the em dash (—) is longest. Each has a distinct job.

Criterion	Hyphen (-)	En dash (–)	Em dash (—)
Width	Shortest	Half an em or N width	One em, the widest
Main job	Joins compound words	Spans, ranges, connections	Breaks, asides, interruptions
Typical spacing	Never spaced	Spaced when marking a parenthetical break	Closed (US) or open (AP, NYT)
Example	state-of-the-art	1990–2000, US–Canada	The result—unexpected—surprised everyone
macOS shortcut	Hyphen key	Option + Hyphen	Option + Shift + Hyphen
Windows shortcut	Hyphen key	Alt + 0150	Alt + 0151
HTML entity	None needed	–	—
Unicode	U+2010	U+2013	U+2014

Hyphen vs em dash: the hyphen joins and the em dash separates. Using an em dash where a hyphen belongs, or a hyphen where a dash belongs, is one of the most common punctuation errors in informal writing. Compound adjectives such as state-of-the-art need hyphens, never dashes.

En dash vs em dash: en dashes express ranges and connections (1990–2000, US–Canada), while em dashes express breaks and asides. When a parenthetical break is needed, US style guides reach for the em dash and several UK publishers reach for a spaced en dash. In narrow newspaper columns the smaller en dash is also preferred purely for space reasons.

Commas, parentheses, and colons: all can do part of the em dash's job. Commas are the most neutral, parentheses are quieter, and the em dash is the loudest of the three. A colon formally announces what follows, while an em dash delivers it more abruptly. Choose according to how much emphasis the aside deserves.

Every major platform has a way to insert the em dash directly. The macOS shortcut is the one most writers remember: Option + Shift + Hyphen.

Platform	Method
macOS	Option + Shift + Hyphen (—); en dash is Option + Hyphen (–)
Windows	Hold Alt and type 0151 on the numeric keypad; en dash is 0150
Linux (GTK)	Ctrl + Shift + U, type 2014, then Enter or Space
Linux (Compose)	Compose key, then - - - (three hyphens), where configured
HTML	— or —
Unicode	U+2014 (decimal 8212)
LaTeX	\textemdash{} or ---
Microsoft Word	Type 2014 then press Alt + X; Word also autoformats --
Mobile (iOS / Android)	Long-press the hyphen key on the on-screen keyboard

The en dash is worth learning at the same time, since it is the right mark for ranges and years. On macOS it is Option + Hyphen, and on Windows it is Alt + 0150 on the numeric keypad.

Before Unicode, the em dash did not exist in the ASCII character set, so writers approximated it with consecutive hyphens. The double hyphen (--) became the widespread typewriter convention for an em dash, and some publishers used three hyphens (---) so that one, two, or three hyphens mapped neatly to the hyphen, en dash, and em dash. The Chicago Manual of Style still described the double hyphen for typewritten manuscripts into its 16th edition.

American comic books kept the double hyphen for decades. Early letterers were not aware of the typographic convention that a typewritten double hyphen should be replaced by an em dash, so the double hyphen became traditional in American comics and continues in computer lettering today.

Modern word processors remove the need to type dashes at all: Microsoft Word, Google Docs, and LibreOffice autoformat two hyphens into an en dash and three hyphens into an em dash as you type. Markdown editors vary, and some treat three hyphens as a horizontal rule, so check the syntax of your tool before relying on it.

In April 2025, Rolling Stone reported on a growing perception that the em dash is a hallmark of AI-generated writing, particularly text from ChatGPT. The idea spread through social media, where users nicknamed it the "ChatGPT hyphen" and advised avoiding it to sound more human.

Several writers defended the em dash as a legitimate, expressive punctuation mark with a long history in human writing. New York Times Magazine editor Nitsuh Abebe theorized that growing unfamiliarity with em dashes reflects writing shifting from edited media toward casual emails and text messages. An OpenAI spokesperson said ChatGPT's style depends on the prompt and is not a reliable indicator of machine authorship.

The practical takeaway: the em dash is a strong mark, and strong marks lose their effect when overused. In any writing, human or machine, a page full of em dashes reads as breathless. Using them sparingly keeps them effective.

Dash conventions vary by country. The United States favors the unspaced em dash (Chicago, APA), while the United Kingdom is split: Oxford University Press uses the unspaced em dash, and Penguin, Cambridge University Press, and Routledge use the spaced en dash.

In Germany and France, the space, en dash, space sequence is the predominant typographic style for parenthetical breaks. Canadian guides (The Canadian Style, Editing Canadian English) and the Australian Style Manual specify a closed em dash between words and numerals. The Australian manual also documents the 2-em rule (⸺) for abrupt breaks in speech: a space precedes the 2-em when a complete word is missing, and no space when only part of a word remains.

The em dash also works as a dialogue marker. The horizontal bar (―), also called the quotation dash, introduces quoted text and is the standard method of printing dialogue in some languages; the em dash is equally suitable when the horizontal bar is unavailable. James Joyce, writing in English, famously used a dash instead of quotation marks for dialogue in Ulysses.