If there is one single character that screams "an AI wrote this," it's the em dash (—).

Go ahead, check for yourself. Ask ChatGPT to write you an essay. It will be filled with them. Now, look at a text message from a friend. Not one in sight. Instead, you'll see the simple hyphen (-).

This tiny, one-character difference is the most consistent and obvious "digital fingerprint" that AI detectors—and savvy readers—look for. Even if you use a paraphrasing tool to "humanize" your text, it will almost always keep these "robot" dashes.

Why Do AIs and Humans Type Differently?

It comes down to two different concepts: **"Publishing" vs. "Typing."**

1. AI "Publishes"

AI models (like GPT-4) were trained on the internet, which includes billions of professionally edited books, newspapers, and academic journals. In the world of professional typesetting and publishing, the em dash (—) is the *only* correct character for a pause or break in thought. The hyphen (-) is only for joining words (like "well-being").

Because the AI was trained on "perfect" text, it "publishes" perfect text.

2. Humans "Type"

Now, look down at your keyboard. You don't have an em dash (—) key. To type one, you have to use a special code (like Alt+0151 on Windows) or let your word processor auto-format it.

When a human is typing quickly—in an email, a school essay, or a text message—they won't bother. They use the tool that's right in front of them: the hyphen (-). It's fast, it's easy, and it gets the same job done.

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Why This Is a "Red Flag"

A text written by a human under normal circumstances will almost always use hyphens for pauses. A text generated by an AI will almost always use em dashes.

An AI detector (or a professor) doesn't even need to read your words. They can just do a "Find and Replace" for "—". If the count is high, it's a massive red flag.

This is just one of several punctuation fingerprints. The same logic applies to “smart” quotes vs. "straight" quotes. These fingerprints are the main reason your "humanized" text still gets flagged.

The Easiest Fix

You could manually hunt down every em dash and replace it with a hyphen. Or, you can use a tool built for this exact problem.

Our Punctuation Chameleon tool was designed to solve this. The "Humanize AI" button instantly scrubs these "robot" punctuation marks, swapping (—) for (-) and (–) for (-), making your text look like it was actually typed by a human.