What sits in your text where nobody sees it
Paste your text to see the invisible control characters and machine punctuation sitting in it. It stays in this browser.
The check runs in your browser. There is no endpoint your text gets sent to, and therefore no daily limit either.
Six things it finds
Two of them are technical defects and always go. The other four are habits you can switch on and off.
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Invisible control characters
- What it is
- Eighteen characters with no width at all, from the zero width space to the directional marks. They sit in the text and appear on no screen, not even to the person who pasted them in.
- Why it gets in the way
- They break everything that compares text. A search no longer finds the word, a spreadsheet import creates a new column, a comparison of two databases reports differences that are not there. And they survive every copy and paste.
- Where it comes from
- They come from text snippets, from PDF exports, from the web and from language models. Some providers insert them deliberately, most appear by accident.
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Spaces that are not spaces
- What it is
- Twelve spacing characters that look like a space: non-breaking, narrow non-breaking, en space, hair space and more.
- Why it gets in the way
- They behave differently. A line break fails where one should happen, a search for two words comes up empty, and in fonts without that character an empty box appears.
- Where it comes from
- From word processors that protect automatically, and from models that aim for correct typography and overshoot.
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Dashes between spaces
- What it is
- The en dash or em dash with a space either side. Not the hyphen inside a word and not the range dash between figures.
- Why it gets in the way
- This is the most conspicuous habit of machine-written text. A piece with forty of them reads dictated rather than written. Comma, full stop and colon do the same work without anybody noticing.
- Where it comes from
- From every large language model. It is the first trait experienced readers spot, and the easiest one to fix.
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Straight quotation marks
- What it is
- The straight inch mark in place of typographic quotation marks.
- Why it gets in the way
- It comes from the typewriter, where every character needed its own key. In typeset text the difference is immediately visible, especially in headings.
- Where it comes from
- From code editors and from any clipboard that has passed through code.
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Three dots instead of an ellipsis
- What it is
- Three separately typed full stops where an ellipsis belongs.
- Why it gets in the way
- Three dots can break apart at the end of a line, the ellipsis is one character and stays together. The spacing is right as well.
- Where it comes from
- From habit. Hardly anyone knows the key combination.
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Double spaces and spaces before punctuation
- What it is
- Two or more spaces in a row, plus the space before a comma, full stop or question mark.
- Why it gets in the way
- It appears when text is assembled from blocks and when words get deleted. In running text it barely shows, in a heading it shows at once.
- Where it comes from
- From any text that has passed through several hands or several sources.
What this tool cannot do
It does not make your text undetectable. Detection services guess from word choice, sentence length and structure, not from control characters. Anyone promising otherwise is selling you something.
What disappears here are real technical faults and typographic habits. The text comes out cleaner and reads less like dictation. That is enough on its own, because a proposal with forty em dashes in it looks generated, even when nobody says the word AI out loud.
Reference
What sits in a text that nobody sees
Two different things carry the handwriting of a machine: invisible control characters that travel along when you copy, and sentence habits that come from routine. The first is measurable, the second is a hint.
Characters without width
A U+200B is a space with no width. It sits between two letters, shifts nothing and is invisible in an editor. It has several relatives, among them U+200C, U+200D and U+FEFF. In ordinary prose none of them has any business being there.
The wrong kind of space
The non-breaking space U+00A0 is correct in typesetting, for instance between a number and its unit. Twelve further variants almost never are, among them the thin U+2009 and the ideographic U+3000. They come from copying out of word processors and chats, and they break line wrapping later.
The dash between spaces
An en dash with a space either side is permitted in German and common in English. What makes it conspicuous is frequency: language models place it where a comma or a full stop would do, several times per paragraph. So we count it rather than forbid it.
Straight quotation marks in prose
Typographic quotes belong in set text, straight inch marks do not. They are a sign that a text has passed through a program that did not know the language. The fault is harmless and fixed in a second.
Three dots as one character
The ellipsis U+2026 looks like three dots but is a single character. It breaks search in a text, because anyone typing three dots will not find it. In set text it is right, in a file that goes on to be processed it usually is not.
Double spaces after a full stop
Two spaces after a full stop come from the typewriter and have been obsolete since hot metal. They do not show in a browser, because HTML collapses them, but they reappear in every further processing step.
A find is not a proof
None of these characters proves that a text came from a machine, and their absence proves nothing either. A paragraph copied out of a PDF carries the same traces. The characters point to the route a text has taken, not to its author.
Why the tool runs without a server
The check happens entirely in your browser. There is no endpoint the text could go to and no buffer it could land in. For a text you are checking before publishing, that is the only setup that works without a leap of faith.
Cleaning is not rewriting
The cleaned text removes the invisible characters and smooths the typography if you ask it to. It changes no word and no sentence structure. What sounds machine-made stays machine-made, and that is a job for you, not for a tool.
Common questions
Does my text leave this machine?
No. The entire check runs in your browser, there is no endpoint a text would be sent to. That is also why the tool keeps working offline once the page is loaded. For completeness: if you accepted measurement, the page reports the number of spots found to our statistics, exactly as the other three tools do. The text itself is never part of it. If you would rather not, decline in the consent dialogue and the tool works exactly the same.
Does this make my text undetectable as AI writing?
No, and anyone promising that is selling you something. Detection services guess from word choice, sentence length and structure, not from control characters. What disappears here are real technical defects and typographic habits. The text gets cleaner and reads better, we claim nothing beyond that.
Why is there no daily limit here?
Because this tool costs us nothing. The other three put a language model to work behind the scenes and are limited to one query a day for that reason. Here your own browser does the computing, so you can check as often as you like.
What exactly are these invisible characters?
Unicode has a set of zero-width characters that control how text is laid out: zero width space, word joiner, soft hyphen, directional marks and several more. They make sense in Arabic and Hebrew script, in breaking long words and in mathematical notation. In ordinary running text they have no business being there.
Can I switch off the typographic changes?
Yes. The toggle above the result separates the two: invisible characters always go, because they do technical damage. Dashes, quotation marks and spacing are only touched if you want them touched. Some texts need the dash, a quotation for instance.
Why do you replace the dash with a comma?
Because a comma carries almost every spot where a dash stands between spaces. A full stop would often be better, but for that a tool would have to understand the sentence. Read through the spots and put a full stop where two main clauses meet.
Do you find filler phrases too?
Not here. The AI design check looks for fifteen of them in a website's source, and the AEO check quotes them verbatim at the spots where your page is missing an answer. This tool works on characters and punctuation only, without judging the content.
What do I do with the result?
Copy the cleaned text back. If you notice your website collecting spots like these regularly, a template with the typography already settled helps, or the AI Website Service.
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