Scan text copied from Grok for hidden Unicode characters, right in your browser. Private and free, since nothing ever leaves your device.
Grok watermark detector
Paste in text copied from Grok and this app scans it for zero-width and non-printing Unicode characters, the kind that take up a position in a string while showing nothing on screen. It's built around a specific search: does Grok hide a watermark in its answers.
Everything runs on your device. There's no account, no upload and no cap on how much text you check.
Workflow
A routine check before anything from Grok ships anywhere.
Why it matters
A zero-width space inside a pasted heading splits the keyword, so your 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 with no obvious cause.
The same characters cause broken find-and-replace, failed CMS saves, and layout problems in exported PDFs. Checking first turns a category of confusing bugs into a five-second fix.
Where they come from
Grok's answer inside X renders in the same interface used for posts, replies and quote-tweets, and copying it can pass through that composer's own text handling, built for links and character limits rather than documents. The standalone Grok app renders in an ordinary chat layout with a separate, simpler copy path.
Neither is a deliberate marker. It's the same kind of formatting residue that shows up wherever rich text is flattened to plain text, shaped by which of Grok's two surfaces produced the copy.
Straight answer
No, and this app doesn't claim otherwise. The same characters show up in text copied from Word, ordinary X posts and other chat tools, so a finding is a formatting lead, not proof of where the words came from.
It also says nothing about whether the text would pass a separate AI detector, since those tools look at sentence patterns and word choice, not invisible bytes.
Who it's for
Anyone moving Grok output into a place that parses text strictly, publishes it, or judges it.
Not a deliberate hidden marker. 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 above and press Scan text. Every hidden character found is listed along with where it sits.
Yes, with no limit on how many checks you run, since scanning happens on your own device.
No. The scan runs entirely in your browser. Nothing is sent to a server, stored or logged.
No. The same characters appear in text copied from Word, ordinary X posts and other AI tools. It's a formatting signal, not proof of source.
Yes. The two follow different formatting paths, so the same underlying answer can carry different invisible characters depending on which one you used.
No. It scans characters, not writing style, and makes no claim about which model produced the text.
No tool can promise that. Detectors weigh sentence patterns and word choice far more than invisible characters.
No. This tool only reports findings. Nothing is altered unless you run the separate cleaner.
Yes, the site's watermark remover strips flagged characters while keeping your wording exactly as written.
No. Since the scan runs on your device rather than a server, there's nothing to cap.
Yes. A zero-width space inside one splits the visible text from what a crawler or CMS actually parses.
Yes. Indentation and line breaks are preserved, and any zero-width characters breaking a build are flagged.
Yes, the characters are language-independent, though the zero-width non-joiner is meaningful in Persian and some Indic scripts and worth a closer look before you act on it.
Text routed through X's post-composer commonly picks up invisible spacing characters on the way to your clipboard, even when nothing looks off.
Not yet. For multiple documents, paste, scan and repeat for now.
Yes, since nothing leaves your device there's nothing to worry about sharing.
Yes, the layout and the scan both work the same on a phone browser.
The scan itself is identical. This page is aimed at people specifically searching for Grok, since X's interface shapes what gets left behind, not the underlying check.
Not necessarily. Both pass through X's own composer, but a direct message box and a public reply box don't always format text identically before it lands in your clipboard.
No, though you can. The app works fine offline once loaded, which is a quick way to confirm nothing is being sent anywhere while you scan.