Runs in your browser. Nothing uploaded, no limit.
Free Grok watermark detector: scan text copied from Grok for hidden Unicode characters in your browser. No upload, no account, no limit.
Grok watermark detector
Paste in a reply copied from Grok 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 Grok 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 Grok splits the keyword, so a slug or anchor stops matching the visible title. A non-breaking space picked up on the way through X's composer 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 through a platform built for posts, not documents.
Where they come from
Grok's answer inside X is rendered in the same interface that handles posts, replies and quote-tweets, and copying it can route through that composer's own text handling. The standalone Grok app renders replies in an ordinary chat layout closer to other assistants, with its own separate copy path.
Neither path involves anything deliberate. It's the same kind of formatting residue that shows up wherever rich text is converted to plain text, just shaped by which of Grok's two homes you copied it out of.
Straight answer
No. A hidden character is a formatting artefact, not a signature. The same characters turn up in text copied from Word, X posts unrelated to any AI, and other chat interfaces, so a finding on its own does not establish that Grok 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 pulling a Grok answer out of X and into an article or a script, where a stray character could split a slug or heading. Developers pasting a Grok-written snippet into a project, where one invisible character is enough to break a build with no visible cause.
Anyone exporting a Grok answer into a document 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 Grok, especially through X's own interface, can carry ordinary invisible characters left over from how that platform's text fields handle a copy.
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, ordinary X posts and other chat interfaces. A finding tells you about formatting, not authorship.
Yes. The two are separate interfaces with separate copy paths, so the same underlying answer can carry different hidden characters depending on which one you used.
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 X's post-composer on the way to your clipboard commonly picks up invisible spacing characters, 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.
No, though you can. The page works fine offline once loaded, which is a quick way to confirm nothing is being sent anywhere while you scan.
The scan itself is identical, the same characters checked the same way. This page is aimed at the specific search for Grok, since X's own interface shapes what gets left behind, not the scan.
Paste, scan, read the findings. Nothing to install, nothing leaving your browser.
Scan my text