About TextNinja

TextNinja takes the invisible characters out of text you paste. Not the words — the debris around them.

Copy a paragraph out of an AI assistant, a PDF or a Word document and you rarely get only what you can see. Zero-width spaces sit between letters. A non-breaking space looks like a normal space but is not one. Curly quotes replace straight ones. None of it shows on screen, and all of it can break a CMS field, a code snippet, a search box or a form that validates its input.

This tool finds those characters, tells you which ones it found and how many, and takes them out when you ask. Your visible text comes back exactly as you wrote it.

Who runs it

One person, in the Netherlands, on a machine in a room here that stays on around the clock. Not a company and not a team — when the site is down, the person noticing and the person fixing it are the same person.

Why it runs in your browser

There is no server doing the work. The entire cleaner is JavaScript on the page you are looking at, which means your text never travels anywhere, there is nothing to store, and there is no reason to ask you for an account or to cap how much you clean. It also means the tool keeps working if this server does not.

What it will not do

It will not help you pass an AI detector. A statistical watermark like SynthID is not a hidden character sitting in the text — it is a pattern in which words the model chose, so the only way to remove it is to rewrite what you wrote. TextNinja rewrites nothing, by design. Tools that promise to strip that kind of watermark while leaving your writing untouched are promising something that cannot be done.