Em Dash U+2014

The em dash (—) is the longest of the three common dashes, roughly the width of a capital "M". It marks a strong break in a sentence: an abrupt turn, an interruption, or an aside that deserves more emphasis than a comma or parentheses. It has been standard English punctuation for centuries. Use the "Copy Em Dash" button above to copy — to your clipboard, then paste it anywhere.

It isn't on any standard keyboard, so casual writing uses a hyphen (-) or double hyphen (--) instead. It is also one of the most talked-about tells of AI-generated text: ChatGPT, Claude, Gemini, and other large language models are widely observed to use more em dashes than typical casual human writing. Because it can break code, CSV files, and search when pasted into technical contexts, this site's viewer flags it alongside invisible characters.

Why AI Models Overuse Em Dashes

The most common explanation: language models learn their style from millions of professionally edited books, academic papers, and newspaper and magazine articles, where em dashes are standard.

Human writers type what's on their keyboard. A hyphen takes one keystroke; an em dash needs a key combination or auto-correct. AI models have no keyboard, so the typographically "correct" em dash costs them nothing extra.

Other AI-Favored Characters

AI models overuse other characters too:

Common Uses (Legitimate)

• Strong break. A stronger pause than a comma or semicolon: The results were clear—the experiment was a success.
• Parenthetical statements. Sets off a phrase with more emphasis than parentheses: The team—all five members—agreed to the plan.
• Interrupted dialogue in fiction. Shows a speaker being cut off: "I was just about to—" He never finished the sentence.
• Replacing colons or semicolons. Introduces an explanation with more weight: There was only one problem—nobody showed up.
• Attribution in quotes. Placed before the author's name at the end of a block quote.

How to Type

Em Dash vs En Dash vs Hyphen

Quick Rules

• To join two words, use a hyphen: self-aware, well-being, twenty-one.
• To show a range or connection, use an en dash: pages 1–10, Monday–Friday, the London–Paris train.
• To add a pause, interruption, or aside, use an em dash: He arrived—finally—at midnight.

When Em Dashes Cause Problems

• CSV and TSV files. Some parsers misread the character or produce encoding errors.
• Command-line arguments. Flags need a regular hyphen, so a pasted em dash can break the command.
• JSON and XML. Valid in JSON strings, but older or ASCII-only systems may choke on them.
• Search and matching. A search for a hyphen won't find an em dash, and vice versa.
• Plain text. Emails, code comments, and commit messages may not render em dashes correctly in every font and terminal.

Detecting Em Dashes

Paste text into our Invisible Character Viewer to see em dashes and other special characters highlighted, with the code point and name on hover.

In code:

// JavaScripttext.includes('\u2014')
// Replace em dashes with regular hyphenstext.replace(/\u2014/g, '-')
// Replace em dashes with double hyphens (common plain-text convention)text.replace(/\u2014/g, '--')

Style Guides and Em Dashes

• AP Style: Em dash with a space on each side: word — word
• Chicago Manual of Style: Em dash with no spaces: word—word
• British style: Often uses en dash with spaces instead: word – word
• AI default: ChatGPT often uses em dashes with no spaces, following Chicago-style American conventions.

Pick one and be consistent.