Scan text copied from DeepSeek for hidden Unicode characters, right in your browser. Private and free, since nothing ever leaves your device.
DeepSeek watermark detector
Paste in text copied from DeepSeek 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 DeepSeek 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 DeepSeek 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 left over from a math expression or a table 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
DeepSeek isn't reached through a single interface. Its own web app and mobile app are one path, but the model is also served through a wide range of third-party hosts, playgrounds and API-based chat clients, each with its own way of rendering Markdown, tables and math notation and converting them to plain text on copy.
That's the real, checkable variable: what a DeepSeek copy carries depends heavily on which interface produced it, not on anything specific to the model's output itself.
Straight answer
No, and this app doesn't claim otherwise. The same characters show up in text copied from Word, Google Docs, PDFs 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 DeepSeek output into a place that parses text strictly, publishes it, or judges it.
Not a deliberate hidden marker. Text copied from DeepSeek can carry ordinary invisible characters left over from converting its formatted Markdown and math notation to plain text.
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, Google Docs, PDFs and other AI tools. It's a formatting signal, not proof of source.
DeepSeek is served through its own app and through many third-party hosts running the same model, each with its own way of converting formatting on copy, so the residue depends on the interface.
Usually not from DeepSeek's own app, which separates the two. Third-party hosts vary, so it's worth checking exactly what you pasted.
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 stray character inside a LaTeX-style expression can break rendering wherever you paste it.
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.
Tables, math notation and nested lists in the rendered output commonly leave invisible spacing characters behind during the copy, 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 DeepSeek, since the copy path varies by source, not the underlying character check.
It changes where the text came from more than what the scan can say. Anyone can run the underlying weights behind their own interface, so a hidden character says even less about provenance for DeepSeek than for a model with one official app.