Ah, the em—dash, or the ChatGPT—hyphen as it has come to be known. It’s now become the infamous punctuation mark in Internet culture.
For pretty much the whole of 2025, people took to LinkedIn to display their alleged knowledge of the tell-tale signs of AI writing… and em—dash was written about time… and time… and time… again. I’m not sure it’s stopped.
ChatGPT loves an em—dash basically. Most human writers don’t. A few do these days, but most don’t. Em—dash is a fairly old fashioned punctuation mark that was used in a lot of old texts, which Large Language Models have trained on. It’s also quite difficult to type on a keyboard.
The best way to remove em—dash is to put it into custom instructions - either in your ChatGPT settings, projects or CustomGPT.
1. To the point
Do not use em dashes. If an em dash would normally appear, use a comma for continuing thoughts or a period if it should be a separate sentence.Via from RunthePrompt.
2. Keep it simple
Systematically replace em-dashes (“—”) with a dot (”.”) to start a new sentence, or a comma (”,”) to continue the sentence.Via Ruben Hassid.
3. You must never…
You must never use em dashes (—) under any circumstance. They are strictly forbidden. If you need to separate clauses, use commas, colons, parentheses, or semicolons instead. All em dashes must be removed and replaced before returning the final output. 2. Before completing your output, do a final scan for em dashes. If any are detected, rewrite those sentences immediately using approved punctuation. 3. If any em dashes are present in the final output, discard and rewrite that section before showing it to the user.
We even made this video about the ‘controversy’:
