About

ChatGPT Em Dash, also known as the ChatGPT Hyphen, refers to the idea that AI-generated text created using ChatGPT tends to overuse the "long hyphen" (—), correctly known as the "em dash." The use of the em dash has been conflated with AI-generated writing since October 2024, with several tech employees, recruiters and marketing specialists on sites like Reddit and LinkedIn pointing to the symbol as a potential shortcut for identifying AI-generated text. While some internet users defended their use of the em dash by pointing to the works of authors like J. R. R. Tolkien and Charles Dickinson or writing styles that make use of it (like AP Style), by early 2025, excessive use of the em dash in internet writing was often equated with AI-generated text.

Origin

An "em dash" is a punctuation mark commonly used in various stylebooks for emphasis to set off a series within a phrase and to signal an abrupt change in a sentence. It can also be used before attribution to an author or composer in some formats and to start lists, as well as seeing use after datelines in articles.^[8]

One of the earliest known internet posts discussing the connection between the em dash and AI-generated text is the now-deleted October 2nd, 2024, post on the /r/ChatGPT^[1] subreddit that reads, "Has anyone noticed how ChatGPT tends to use em dashes frequently? They're not on a keyboard, so it's usually a dead giveaway that something's written by AI."

Similar posts made on October 5th and November 14th, 2024, show Redditors^[2][3] /u/BaggyBoy and /u/RealJoshuaWall discussing how AI-generated text appears to be rife with the use of the em dash, with /u/RealJoshuaWall noting that ChatGPT had a difficult time avoiding the use of the punctuation even when specifically asked not to use it.

Spread

By early 2025, discussions about ChatGPT em dash overuse spread to platforms such as LinkedIn,^[4] with user Isabella Williamson writing, "I—keep—seeing—weird—long—dashes—in—posts… [Who] else is seeing them more often? Yes, this is the work of ChatGPT." The January 2025 post gathered over 40 reactions and 60 comments in four months.

Not everyone agreed with Williamson's belief that the use of the em dash is indicative of AI-generated text, including user Matt Durante, who posted a video showing himself reading The Lord of the Rings by J. R. R. Tolkien to LinkedIn in February 2025,^[5] saying, "AI uses em dashes because writers use em dashes. I use em dashes every day and I am categorically a writer. AND I hate gen AI writing."

On February 11th, 2025, X user and Life & The Lindy Effect author Paul Skallas tweeted, "A shortcut for detecting if something is written with AI is they all use this symbol "—" throughout the writing. It's relatively rare when a human uses it, maybe once or twice, if that. But AI chats love using it. No clue why." The post gathered over 11,000 likes in two months.^[6]

On March 22nd, the Instagram^[7] page @luxegen_official discussed a brand announcement by the fast fashion company PrettyLittleThing in which a follower commented on the announcement's repeated use of the em dash, calling it the "Chat GPT hyphen." The post gathered over 9,000 likes in two weeks.

Also on March 22nd, 2025, a post asking, "How did the em dash become the signature AI detection punctuation?" appeared on the /r/ChatGPT^[9] subreddit, receiving over 1,400 upvotes and 270 comments in 16 days. The post from Redditor wawawaaaaawa read:

Any writer worth their salt knows when to use em dashes to denote breaks in sentences. I almost instinctively type 'alt + 0151' when typing.

But since AI generated text became mainstream, even humans who use em dashes get perceived as AI.

Crazy how an entire punctuation mark has been invalidated. Thanks ChatGPT.

Various Examples

Search Interest

External References