AI Watermark Checker

AI Watermark Checker

Not sure whether a document carries hidden characters? Paste it below. The checker lists every invisible or non-standard character it finds — what it is, how many, and where it came from — before you decide to clean anything.

Runs entirely in your browser — nothing you paste is uploaded.

How it works

  1. 1. Scan. The checker walks every character in your paste and flags anything invisible or non-standard: zero-width characters, special spaces, soft hyphens, directional marks, curly punctuation, and dashes.
  2. 2. Review. You see a per-character report — what was found and how many — before anything changes.
  3. 3. Clean. With the options you picked, flagged characters are deleted or normalized to their plain equivalents. Copy the result with one click.

Everything happens locally in your browser. There is no upload, no account, and no length limit.

Frequently asked questions

Do all AI models leave these characters?

It varies by model, app, and even copy path. Chat interfaces add non-breaking spaces and smart punctuation through their renderers; some pipelines add zero-width characters. The only way to know what a given paste contains is to scan it — the checker above shows exactly what it found.

Can hidden characters prove text is AI-generated?

Not on their own. Plenty of human-made documents contain non-breaking spaces and smart quotes — word processors insert them constantly. A cluster of zero-width characters in plain prose is unusual and worth a look, but treat any single signal as a hint, not a verdict.

Is my text uploaded anywhere?

No. The cleaner runs entirely in your browser — nothing you paste ever leaves the page. You can disconnect from the internet after the page loads and it keeps working.

Clean bytes are step one. Natural writing is step two.

Ask GPT, Claude, Gemini, and more to rewrite the same passage side by side, then keep the version that actually sounds human. One prompt, every model.

Compare rewrites on Admix

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