Runs in your browser. Nothing uploaded, no limit.
Free Gemini watermark detector: scan text copied from Gemini for hidden Unicode characters in your browser. No upload, no account, no limit.
Gemini watermark detector
Paste in a reply copied from Gemini and this tool scans it for the zero-width and non-printing Unicode characters a chat interface can leave behind, without changing anything visible. It's built for the question people actually search: does Gemini hide a watermark in its text.
The scan runs entirely in your browser. Nothing is uploaded, there's no account, and there's no limit on how much text you check.
How it works
It takes seconds and nothing you paste leaves this page.
Why it matters
A zero-width space inside a heading pasted from Gemini splits the keyword, so a slug or anchor stops matching the visible title. A non-breaking space picked up from a Google Docs export can break a shell command, a config file or a CSV column without any visible sign of why.
The same characters cause broken find-and-replace, failed CMS saves, and layout problems in exported PDFs. None of it requires anything unusual, it's a side effect of moving text between formatted surfaces.
Where they come from
Gemini is deeply tied into Google Docs, Sheets and Gmail, with buttons to export a draft straight into one of them. Each of those apps has its own typography engine that reformats punctuation and spacing as text moves through it, which is a common source of the non-breaking spaces and smart quotes a scan finds.
None of it is a deliberate marker. It's the same kind of formatting residue that shows up copying text out of any word processor, just routed through Google's specific tools instead of Microsoft's.
Straight answer
No. A hidden character is a formatting artefact, not a signature. The same characters turn up in text copied from Word, plain Google Docs and other chat interfaces, so a finding on its own does not establish that Gemini specifically produced the words.
It also isn't evidence about whether text will pass a separate AI detector. Those tools weigh sentence patterns and vocabulary, not invisible bytes. Treat a finding as a formatting lead, nothing more.
Who uses it
Writers and editors moving a Gemini draft out of Google Docs and into a CMS, where a stray character could split a slug or heading. Developers pasting a Gemini-written snippet or config file into a project, where one invisible character is enough to break a build with no visible cause.
Anyone exporting a Gemini answer into a spreadsheet or data file where hidden characters cause parsing errors downstream runs this as a routine check before it ships.
FAQ
Everything below is answered in full, nothing to click open.
Not in the sense of a deliberate hidden signal. Text copied from Gemini, especially through Google Docs or Sheets, can carry ordinary invisible characters left over from those apps' own formatting and typography features.
Paste it into the box above and press Scan text. Every hidden character is listed with where it sits.
Yes, and there's no limit on how many times you use it, since scanning runs in your browser.
No. Scanning runs entirely in your browser. Nothing is transmitted, stored or logged.
No. The same characters appear in text copied from Word, plain Google Docs and other chat interfaces. A finding tells you about formatting, not authorship.
Google Docs auto-formats punctuation and spacing as part of its typography, converting straight quotes to curly ones and inserting non-breaking spaces in certain spots, which is common regardless of what wrote the underlying words.
No. The scan looks at characters, not writing style, and makes no claim about which model produced the words.
No tool can promise that. Detectors judge sentence patterns and vocabulary, not invisible bytes.
No. This detector only scans and reports. Nothing is removed or rewritten here.
Yes, the site's watermark remover strips what this scan finds while leaving your wording untouched.
Yes. There's no length cap, since scanning runs on your own device rather than a server.
Yes. A zero-width space inside one splits the keyword, so the visible title and the slug or anchor stop matching.
Yes. Zero-width characters inside a snippet can stop it compiling with no visible cause, and the scan finds them.
The characters themselves are language-independent. The zero-width non-joiner is meaningful in Persian and some Indic scripts, so review those flags before removing anything.
Text routed through Google Docs, Sheets or Gmail commonly picks up invisible spacing and typography characters during those apps' own formatting, even when nothing looks off on screen.
Not yet. For several documents, paste, scan, copy the findings and repeat for now.
Yes. Nothing leaves your browser, so it's fine for drafts you haven't shared anywhere.
Yes. The page works the same in a mobile browser, no app required.
The scan itself is identical, the same characters checked the same way. This page is aimed at the specific search for Gemini, since Google's own apps are what shape what gets left behind, not the scan.
Paste, scan, read the findings. Nothing to install, nothing leaving your browser.
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