Style Mirror

What it measures

Twenty things that together make writing recognisable. How long your sentences run and how much the length varies. How long your paragraphs run. How often you use semicolons, colons, parentheses, em dashes, questions, exclamation marks, ellipses and quotation marks, each counted per thousand words. Whether you contract (don't, it's), how often you write in the first person and how often you address the reader. How heavy your vocabulary is, measured by word length and by variety. What words you open sentences with, how often you open with a transition word such as However or Also, and which content words you use more than most people would. Formatting habits: bullets, headings, bold.

None of these is a judgment. Short sentences are not better than long ones and semicolons are not a vice. The point is that the mix is yours, and it is more stable than most writers expect. Once you can see it, you can protect it, develop it or deliberately break it.

What it does not do

It does not rewrite, paraphrase, humanize or "improve" anything. It does not detect AI, and a low match score is not evidence that a draft came from a model. It does not upload your text: the page is a single script that runs in your browser, and you can read it at /mirror.js. It does not keep anything unless you click Save, and then it keeps the numbers, not the words, in your own browser.

How to use it well

Pick the register you care about and feed it two or three real examples of that register. Read the plain-English summary first; the table underneath is there when you want the exact numbers. Then try a draft. If it drifts, the findings tell you where: longer sentences than usual, no contractions, a punctuation mark you never use. Decide for yourself whether the drift is a problem. Sometimes a new register calls for a new voice, and the tool is there to make the change visible, not to stop it.

If you are a student or a professional who may one day be asked to prove you wrote something, download the profile and keep it with your drafts. A dated record of your measured voice, next to version history and notes, is exactly the kind of process evidence our guide on being flagged by a detector recommends. It is far stronger than any detector score, in either direction.

Why this tool is on a site about watermarks and detectors

Because the whole field exists in the gap between a model writing text and a person reading it, and the one thing in that gap a writer actually owns is their own voice. Detectors are fallible, marks are removable, and the arms race between humanizers and detectors has no end. A writer who knows how they write, and can show it, is outside that fight. The directory maps the tools that try to tell human from machine. Style Mirror helps the human side be legibly human.

Questions

Does Style Mirror rewrite my text?

No. It measures and compares. It never changes a word, and it has no rewrite, paraphrase or humanize function. If you want your writing to sound like you, the way to get there is to write it, and this tool shows you what "like you" measures as.

Is this an AI detector?

No. It does not guess whether text was written by a model, and a low match score does not mean a draft is AI-generated. It means the draft differs from your own samples in measurable ways: sentence length, punctuation, person, vocabulary. People drift from their own voice all the time, especially when tired, rushed or writing in a new register.

Where does my writing go?

Nowhere. The page runs entirely in your browser. There is no upload, no account and no analytics on what you paste. If you click Save, the profile (the numbers, not your text) is kept in your own browser storage until you click Forget.

How much writing do I need?

At least 120 words to get a reading, 300 or more for a steady one, and a thousand or more for a profile you can trust. Use two or three pieces in the register you care about: an essay for essays, work email for work email. Mixing registers blurs the picture.

Why would a writer want this?

Three reasons people have told us. To see their habits plainly before an editor does. To check that a draft written in a hurry still sounds like them. And, for students and professionals who may be asked to prove authorship, to have a dated record of their own measured voice alongside their drafts, which is the kind of process evidence our guides recommend.

Can I make AI tools write in my voice?

Not with this page, which only measures. CogmemAi Voice, made by the same publisher as this site, turns your writing samples into a profile and a rule set that every connected AI follows, and it scores drafts against them. Style Mirror shows you the measurements; Voice applies them.