Nothing screams AI quite like an em dash — and yes, that was one. Paste your text, pick what they should turn into, and the spacing gets put back properly on the way out.
Because the books, magazines and blogs a model learned from are full of them. The em dash is the punctuation mark of edited, typeset prose — it is how a professional writer slips a second thought into a sentence without starting a new one. There is one in that sentence. There are several more on this page. I will let you draw your own conclusions about who wrote it.
The trouble is that almost nobody types one. It is not on your keyboard, and the people you write for are not expecting it. So a paragraph with four of them reads as borrowed rather than written, even to a reader who could not tell you what the character is called.
That is usually why people end up here: not because the dash is wrong, but because it is not theirs.
Removing a character is a one-line find-and-replace. Anybody can do that in a text editor, and the result is the reason you are reading this instead.
Em dashes turn up two ways. Typeset text sets them tight, like—this. Web text sets them loose, like — this. Swap the character on its own and the first becomes like,this and the second becomes like , this. Both are wrong, and both are the kind of wrong you only spot after publishing.
So this tool takes the spaces on both sides with it and builds the gap back to suit what you chose. A comma always lands as a, b. A hyphen keeps whatever spacing was there. Removing the dash entirely leaves one space if there was one, and closes the word up if there was not.
Line breaks, always. The pattern only ever eats horizontal spaces and tabs, so a paste from a CMS comes back with its paragraphs and list items exactly where they were.
The en dash is left alone too, unless you tick the box. It looks similar, but it is doing a job: in pages 5–18 or Monday–Friday it means "to", and turning it into a comma would make nonsense of the range.
A dash sitting alone at the start or the end of a line is dropped rather than converted — a line that began with a dash and ends up beginning with a stray comma is worse than where it started.
No, and anyone telling you otherwise is selling something. Detectors do not look for em dashes. They score sentence-level patterns - how evenly the rhythm runs, how predictable each next word is - and swapping punctuation leaves every bit of that where it was. Use this because you want the text to sound like you, not because you think it launders it. If a detector really is the problem, the only fix is rewriting the sentences yourself. Ugh.
A comma, nine times out of ten. An em dash is nearly always standing in for a comma or a full stop, so a comma keeps the sentence reading the way it was written. Reach for a hyphen only where the dash was joining two halves of a compound, and for nothing at all where it was padding two words that belong together. If the result reads oddly, that is usually the sentence asking to be split in two.
Length, and the job each one does. The hyphen is the short one on your keyboard and it joins words, as in well-known. The en dash is the width of an n and it means to, as in 5-18. The em dash is the width of an m and it interrupts a sentence. Only the last of the three marks text as machine-written, which is why this tool starts with it on its own.
You can, and for a paragraph or two it works. Then the instruction drifts out of reach and they come back, usually in the long bit at the end you skimmed. Cleaning the output afterwards takes a second and does not depend on the model remembering anything.
Those are handled too, and the box is ticked by default. The two-em dash, the three-em dash and the horizontal bar are separate Unicode characters, but at reading size they are indistinguishable from an ordinary em dash - so leaving them behind means finding one stray dash in the copy a week later and wondering why your search never caught it.
There is no fixed limit. A chapter-length paste is handled instantly. Something enormous will make the page think for a moment before it comes back.