ClaudeClean

PUNCTUATION FIX, UPDATED OCTOBER 2026

Remove em dashes from AI text, with the right punctuation instead

ChatGPT and Claude lean on the em dash so heavily that readers now treat it as an AI tell. Here is what each dash should become, how to replace them in Word, Google Docs and code editors, and what removing them does not change.

Scan my text free Updated

Short answer

To remove em dashes from AI text, find each — (U+2014) and replace it with the punctuation the sentence needs: a comma for an aside, a colon before an explanation, parentheses for a side note, or a period between two full sentences. In Word, search for ^+. Em dashes are a style habit, not the Claude watermark.

SIX REPLACEMENT RULES

What should you replace an em dash with?

A blanket swap to commas breaks about as many sentences as it fixes. Match the replacement to the job the dash was doing.

Comma

Before
The report—which took three weeks—arrived late.
After
The report, which took three weeks, arrived late.
Use when
The dashes wrap a light aside that the sentence still reads well without.

Colon

Before
Only one thing mattered—speed.
After
Only one thing mattered: speed.
Use when
What follows explains, names or lists what came before.

Parentheses

Before
The tool—free for 2,000 characters—runs in the browser.
After
The tool (free for 2,000 characters) runs in the browser.
Use when
The aside is a side note, a number or a detail the reader can skip.

Period

Before
We ran it twice—the results matched.
After
We ran it twice. The results matched.
Use when
Both sides are full sentences. This is the most common AI pattern and a comma here creates a splice.

Semicolon

Before
The draft was long—the edit was longer.
After
The draft was long; the edit was longer.
Use when
Two full sentences are closely tied and you want to keep them in one line.

En dash or the word to

Before
Pages 10—20, 2019—2024
After
Pages 10–20, or 2019 to 2024
Use when
The dash marks a range of numbers, dates or times. Style guides use the shorter en dash here.

TRY THE RULES

Fix the dashes one by one

Paste your own text or edit the sample. Pick a default, then click any dash to cycle it through the rules.

Default

Result

5 em dashes, 1 range to en dash

The reportwhich took three weeksarrived late. We ran it twiceThe results matched. Only one thing matteredspeed. Read pages 10–20 before Friday.

Runs in your browser. Nothing is sent anywhere.

KNOW THE CHARACTERS

What is the difference between an em dash, en dash and hyphen?

Five characters look alike on screen. Find and replace treats them as different, so search for the right one.

Em dash — (U+2014)
The long dash AI models overuse, for breaks and asides. Type it with Alt+0151 on Windows or Option+Shift+Hyphen on a Mac, per Computer Hope.
En dash – (U+2013)
Half an em dash, used for ranges such as 9–5 or 2019–2024. Alt+0150 on Windows, Option+Hyphen on a Mac. Keep these when they mark a range.
Hyphen-minus - (U+002D)
The key on every keyboard. Joins compound words like well-known and doubles as a minus sign in code. Never replace these in bulk.
Minus sign − (U+2212)
The true mathematical minus, slightly longer than a hyphen. It shows up in pasted formulas and will not match a search for a hyphen or a dash.
Horizontal bar ― (U+2015)
Used to introduce quotations in some languages and typesetting styles. Rare in AI output, but it can sneak in through copied text.
Two hyphens in a row
The typewriter stand-in for an em dash. Word and many editors convert a typed pair of hyphens to a real dash as you type, which is how dashes return after you remove them.

TYPING THEM

Where each dash lives on the keyboard

Pick a combo. Keys light up in the order you press them.

Mac

Option+Shift+Hyphen

word—

U+2014, em dash

Shortcuts from Computer Hope, the same ones listed in the glossary above.

OR LET THE CLEANER DO IT

Swap the dashes, or keep the ones you chose.

ClaudeClean's local clean turns em dashes into commas in your browser. Its rewrite drops AI dashes too, unless you tick Keep em dashes, which keeps the ones in your source and adds none. No detector result is promised.

Strip em dashes from my text Pro is $5/month
  • 300 rewrite credits a month
  • 20,000 characters per request
  • .txt, .docx and .pdf files

FIND AND REPLACE

How do you find and replace em dashes in Word and Google Docs?

Six steps that cover the places AI text usually lands: a Word file, a Google Doc, a code editor or a spreadsheet.

  1. 01

    Microsoft Word: search with ^+ and ^=

    Press Ctrl+H. In Find what, type ^+ for em dashes or ^= for en dashes, the special codes listed in Word's Special menu. Use Find Next rather than Replace All, so you can pick the right punctuation each time.
  2. 02

    Word: stop it adding new ones

    Word turns two typed hyphens into a dash as you type. Clear the Hyphens (--) with dash option under File, Options, Proofing, AutoCorrect Options, AutoFormat As You Type.
  3. 03

    Google Docs: paste the dash into Find

    Press Ctrl+H (Cmd+Shift+H on a Mac). Copy one em dash from your document, paste it into Find, and type a comma and space into Replace with. Step through matches with Replace, not Replace all.
  4. 04

    VS Code and code editors: use a regex

    Open Replace (Ctrl+H), switch on regex (Alt+R) and search for \s*\u2014\s*. Replace with , . For en dashes in ranges, search for \u2013 separately and leave them alone.
  5. 05

    Spreadsheets: SUBSTITUTE with UNICHAR

    In Google Sheets or Excel, =SUBSTITUTE(A1, UNICHAR(8212), ", ") swaps every em dash in a cell. 8212 is the decimal code for U+2014, and 8211 is the en dash.
  6. 06

    Read it back once

    Search the result for double commas, run-on sentences and broken number ranges. Then read it aloud: a dash that became a comma between two full sentences needs a period instead.

STEPS 1 AND 2, PLAYED OUT

Find Next, pick the punctuation, then switch off the source

Each match gets the replacement its sentence needs. Then the AutoFormat option stops two typed hyphens from becoming a dash.

Illustration

Sample document. Search codes ^+ and ^= from Word's Special menu, as listed in step 1.

WHERE THE HABIT COMES FROM

Why does ChatGPT use so many em dashes?

No lab has published a confirmed cause. The best public analysis points at old books in the training data.

~0.35%

Share of all words that were em dashes in English print around 1860, the historical peak

Sean Goedecke

1,728

Em dashes in Moby-Dick, the kind of 19th-century book that ends up in digitized training sets

Sean Goedecke

~10x

How many more em dashes GPT-4o used than GPT-3.5, which barely used them

Sean Goedecke

3.28x

GPT-4.1's em dash rate in essays compared with human writers, in a finding cited by McGill

McGill Office for Science and Society

The leading theory, and what it rules out

Goedecke argues labs added large sets of digitized late 1800s and early 1900s print books, which use em dashes far more than modern prose. He judged the popular theory about Nigerian English feedback raters weak, since em dashes make up only about 0.022% of words in that writing. For all six theories graded against 2026 data from 12 models, read why AI uses em dashes.

THE NUMBERS, DRAWN

The em dash numbers, side by side

Each pair shares one scale, so the length of the orange bar is the gap.

Em dashes as a share of all words

English print, around 1860~0.35%
Nigerian English writing~0.022%

Source: Sean Goedecke

Model against model

GPT-4o~10x
GPT-3.5, which barely used them1x

Source: Sean Goedecke

Model against human essays

GPT-4.13.28x
Human writers1x

Source: McGill OSS

Moby-Dick

0

em dashes in one 19th-century novel. One square per dash.

Source: Sean Goedecke

Figures from Sean Goedecke and the McGill Office for Science and Society, the same sources as the cards above.

DASHES IN, PUNCTUATION OUT

Clean em dashes in the browser, then fix the rest of the habit

The dash swap is instant and local. The rewrite handles the sentences around it.

01

> source text

Paste the AI draft

Paste ChatGPT or Claude text, or upload a .txt, .docx or .pdf. Up to 2,000 characters work without an account.

02

scan report

3 zero-width1 soft hyphencleanable signals2

Swap dashes locally

With the em dash option on, the clean replaces each em dash and its spaces with a comma, along with hidden characters. Check the diff for spots that needed a colon or a period.

03

before → after

clearusefulanswer

Copied ✓

Rewrite the dash-heavy sentences

The rewrite avoids em and en dashes and turns any leftover into a comma or a period. Tick Keep em dashes to keep the ones already in your source.

PRICING

Clean the text free. Rewrite more with Pro.

The scan and hidden-character cleanup are free. Pro adds room for rewrites and files.

PRO

CLAUDECLEAN PRO

ClaudeClean Pro

$5/ month

Cancel anytime.

  • 300 credits every month (≈300,000 characters of rewriting)
  • 20,000 characters per request
  • Clean .txt, .docx and .pdf files
  • Light / medium / strong intensity
  • Dashboard with history
Checking account…

Free: 10 credits a month with an account, or try 2,000 characters right here without one. Strong rewrites cost 2× credits.

KEEP OR CUT

When is an em dash fine, and when should you cut it?

The em dash is not wrong. Overuse in plain text is what readers notice.

Fine to keep

  • Dialogue that breaks off. A speaker cut off mid-sentence needs a dash or an ellipsis.
  • One deliberate emphasis per page. A single well-placed dash reads as a choice, not a tic.
  • Your own voice. If you used em dashes before chatbots, there is no reason to stop.
  • House styles that require them. Some publishers set dashes as part of their style guide.

Worth cutting

  • Several per paragraph. Density is what makes text read as generated.
  • Joining two full sentences. A period is clearer and is the usual fix.
  • Before a punchline or summary. The 'one more thing' dash is the pattern readers spot first.
  • Emails, reports and school work. Plain-register writing rarely needs them at all.

DENSITY, NOT THE DASH

One dash reads as a choice. Five read as a habit.

Same paragraph, same words. Pick how many dashes it carries.

Illustration
Dashes

Our new onboarding flow is live—it cuts setup time in half. Most people finish in one sitting; a few need a second pass. The checklist (five steps in total) sits on the home screen. The best part: it's free.

1dash in 39 words

Fine to keep

One deliberate emphasis reads as a choice, not a tic.

PUNCTUATION VS PROVENANCE

Does removing em dashes remove the AI watermark?

No. These are two separate things that people often mix up.

Em dashes are not a watermark

Anthropic says nothing is added to Claude's text and there are no hidden characters. Its watermark is a statistical pattern spread across the word choices, so replacing a handful of dashes leaves that pattern in place.

WHAT IT CHANGES

How the text reads

Removing dashes changes rhythm and register. That affects human readers and the style classifiers behind many AI scores.

WHAT IT LEAVES

The word-choice pattern

The statistical watermark lives in hundreds of word choices. A few punctuation marks are a tiny share of the text that gets scored.

WHAT DOES CHANGE IT

Replacing the words

Anthropic says a complete rewrite where every word is replaced will remove the mark. That is a rewrite, not a punctuation pass.

PREVENTION

How do you stop ChatGPT and Claude from using em dashes?

Telling the model works better now than it did, but check the output anyway.

If you tell ChatGPT not to use em-dashes in your custom instructions, it finally does what it's supposed to do!
Source: Sam Altman, November 2025, via Business Insider

The phone runs the rule from the ChatGPT card below. Paste it once, then check the next long reply, since users still report misses.

ONE STANDING RULE

Tell it once, check the next reply

Illustration

Sample reply written for this page. Users still report misses, so do a final find pass.

CHATGPT

Custom instructions

Add a standing rule: never use em dashes or en dashes; use commas, colons, parentheses or periods. Altman called the fix a small but happy win, and users still report misses.

CLAUDE

Preferences or project instructions

Put the same rule in your profile preferences or a project's instructions so every chat starts with it, then spot-check long answers.

ANY MODEL

Say what to use instead

A ban alone leaves the model reaching for its habit. McGill's Office for Science and Society notes the em dash habit resists prompt restrictions, so name the replacement and do a final find pass.

AFTER THE SWAP

What breaks when you replace em dashes in bulk?

A Replace all pass is fast. These are the six things to check afterwards.

SPLICES

Comma splices

Two full sentences joined by a comma read as a run-on. Split them with a period.

DOUBLES

Double commas

A dash next to an existing comma becomes , , after the swap. Search for a comma, a space and a comma to catch them.

RANGES

Broken number ranges

A range like 2019—2024 turns into "2019, 2024", which reads as a list. Use an en dash or the word to.

CODE

Hyphens and minus signs in code

Never replace hyphens in bulk. Command flags, file names and arithmetic depend on them.

AUTOCORRECT

Dashes that come back

Editors that turn two typed hyphens into a dash will reinsert them as you keep typing. Turn the substitution off.

LOOK-ALIKES

Dashes your search missed

A search for U+2014 skips the en dash, the minus sign and the horizontal bar. Run one search per character.

HOW IT BECAME A TELL

When did the em dash become an AI tell?

A short history of the argument, with the original posts and articles.

  1. FEBRUARY 2025

    The em dash gets called out

    Writer Paul Skallas posted that the em dash had become a sign of AI writing. The Daily Dot covered the pushback from writers who had used the dash for years.

  2. JULY 31, 2025

    Writers defend the dash

    The Federalist argued that AI using the em dash is no reason for human writers to give it up.

  3. AUGUST 25, 2025

    Slate asks if ChatGPT ruined it

    Slate's ICYMI podcast devoted an episode to the em dash as a ChatGPT tell, embedded below.

  4. OCTOBER 30, 2025

    The training data theory

    Sean Goedecke traced the habit to digitized older books and measured how dash use grew from GPT-3.5 to GPT-4o and GPT-4.1.

  5. NOVEMBER 2025

    OpenAI ships a fix

    Sam Altman said ChatGPT now respects a no em dash rule in custom instructions, reported by Business Insider.

  6. MAY 8, 2026

    Still a habit

    McGill's OSS cited a finding that GPT-4.1 uses em dashes at 3.28 times the human rate in essays.

WATCH

Slate on how ChatGPT changed the em dash

ChatGPT Has Ruined the Em Dash | ICYMI Podcast by Slate. Candice Lim and Kate Lindsay discuss whether writers should give up the em dash.

SOURCES

Sources on em dashes in AI writing

Data, history and the tools behind each step on this page.

SEAN GOEDECKE

Why do AI models use so many em dashes?

Historical rates, GPT-3.5 vs GPT-4o counts and the training data theory.

View source

MCGILL OSS

Why did LLMs steal our em dashes?

GPT-4.1 at 3.28 times the human rate; the habit resists prompt rules.

View source

BUSINESS INSIDER

Sam Altman says OpenAI fixed it

Custom instructions now stop ChatGPT's em dashes, November 2025.

View source

DAILY DOT

The em dash as an AI tell

The February 2025 post that started the debate, and writers' replies.

View source

THE FEDERALIST

Real writers should keep the em dash

The case for keeping the dash in human writing.

View source

ANTHROPIC

Claude's text watermark

No hidden characters; the mark lives in word choices, not punctuation.

View source

DUMMIES

Special characters in Word find

The ^+ em dash and ^= en dash search codes.

View source

COMPUTER HOPE

Typing en and em dashes

Windows Alt codes and Mac keyboard shortcuts for both dashes.

View source

SLATE, YOUTUBE

ChatGPT Has Ruined the Em Dash

ICYMI podcast episode, August 2025.

View source

FAQ

Em dashes in AI text: FAQ

Use find and replace. In Word, search for ^+ (em dash) and ^= (en dash). In Google Docs, paste the dash into Find. In VS Code, use the regex \s*\u2014\s*. Then pick a comma, colon, parentheses or period per sentence.
Nobody has a confirmed answer. Sean Goedecke's best explanation is training on digitized late 1800s and early 1900s books, which used far more em dashes than modern prose. He found GPT-4o used about 10 times more than GPT-3.5.
Not on its own. Writers used em dashes long before chatbots, and use peaked around 1860. A heavy, regular pattern of them in plain business or school text is what makes readers suspect AI.
No. Claude's watermark is a statistical pattern across its word choices, with no hidden characters. Swapping a few dashes for commas changes punctuation, not the pattern. No detector result is promised.
Add a line to ChatGPT's custom instructions, such as: never use em dashes; use commas, colons or parentheses. Sam Altman said in November 2025 that ChatGPT now follows this, though users still report misses.
It depends on the job the dash was doing. Commas for a light aside, a colon before an explanation, parentheses for a side note, a period between two full thoughts, and an en dash or the word to for ranges.

Keep reading

What is the Claude watermark?How to remove the Claude watermarkWatermark vs hidden charactersDoes paraphrasing remove it?Claude humanizerOpen the cleaner