Grok watermark remover
xAI’s Grok API can now watermark the text it generates. The mark is SynthID-Text, the statistical method Google DeepMind published, and it stays off unless a team’s admin turns it on for a model. xAI has announced no text watermark for the Grok app or Grok on X. Unmark rewrites the wording, which is what removes a statistical watermark, and strips hidden characters in the same pass.
It dependsThe Grok app has announced no text watermark, so stripping hidden characters is enough. Text from the Grok API is watermarked only if the developer’s team switched it on; if it was, rewrite it.
▸Hidden-character optionscore invisibles, tags & private-use are always removed
Facts checked against the sources below on .
Does Grok watermark its text?
Through the API, it can. xAI’s developer documentation describes “Output Watermarking” for text from grok-4.7, grok-4.6, grok-4.5, grok-4.3 and the three grok-4.20 models, covering ordinary replies, structured outputs and tool-call arguments. The page, last updated on November 9, 2026, says it is off by default: a team admin switches it on per model in the console, it then applies to every API key on the team, and some models can be locked on. xAI presents it as a way to help meet the EU AI Act.
News reports in early November said the watermark would be on by default from November 7. xAI’s own page says otherwise, so we follow the page. For the Grok app and Grok on X, xAI has published nothing about marking text: its app FAQ mentions a watermark on generated images and videos only.
How the Grok API watermark works
xAI says its implementation uses SynthID-Text. While the model writes, the watermark slightly shapes which tokens it picks, so nothing is added to the text: no characters, no markup, no hidden text. Detection is statistical, and longer text gives a stronger signal.
Developers can tell whether a response was marked from its x-watermark header: “true” means that output was generated with the watermark. The header does not travel with the text. Once the text is copied elsewhere, only xAI’s detection API can check it, and access to that is granted by application.
How to remove a Grok watermark
A statistical watermark sits in the wording, so removing it means changing the wording. Paste the text into the tool above and click Remove watermark: Unmark rewrites it paragraph by paragraph and keeps your names, numbers and layout. If the text came from the Grok app, where no text watermark is announced, “Strip hidden chars only” is enough: it removes invisible characters in your browser and leaves your wording alone.
No one outside xAI can verify a particular text, because the detector is not public, so treat removal as best-effort. xAI’s acceptable use policy also prohibits removing watermarks or other provenance signals from Grok output; check the terms that apply to you.
We tested this with Google’s open-source SynthID-Text on 120 passages: after 10% of the words were swapped for synonyms, 92% were still detected; after a full rewrite with Unmark, 3% were. Read the study.