OpenAI introduces textGrain watermarking for EU compliance

OpenAI textGrain EU AI Act watermarking ChatGPT

OpenAI has announced the deployment of textGrain, a statistical watermarking technology designed to identify text generated by ChatGPT and Codex within the European Union. This move is intended to comply with the transparency requirements of the EU AI Act, which mandates that providers make AI-generated content identifiable.

Unlike visible markers, textGrain functions by imperceptibly altering the mathematical selection of words during the generation process. This method embeds a statistical signature into the text without changing its layout or typography. While the technology is designed to be resilient to minor edits, human rewriting or translation can significantly reduce its detectability.

Access to the official detection tool is currently restricted to approved researchers and expert organizations, meaning widespread use by general businesses is not yet available. For API clients, the watermarking option must be enabled manually, placing the regulatory responsibility for traceability on technical integrators.

Entities

Anthropic · ChatGPT · Claude · European Union · Google · OpenAI

Claims

What the coverage asserts, and how many sources carry each claim.

[○ 1 SOURCE] API clients must manually activate the watermarking option. dcod.ch
[○ 1 SOURCE] Anthropic announced plans to implement text watermarking for Claude on August 14, 2026. weekly.ascii.jp
[● 2 SOURCES] The technology aims to comply with the EU AI Act. dcod.ch · weekly.ascii.jp
[○ 1 SOURCE] Google previously introduced SynthID for Gemini text in May 2024. weekly.ascii.jp
[● 2 SOURCES] OpenAI introduced textGrain to identify ChatGPT and Codex text in the EU. dcod.ch · weekly.ascii.jp
[○ 1 SOURCE] Human rewriting or translation significantly reduces the effectiveness of detection. dcod.ch
[○ 1 SOURCE] Official detector access is restricted to approved researchers and expert organizations. dcod.ch
[● 2 SOURCES] textGrain uses a statistical method to mark text without visible characters. dcod.ch · weekly.ascii.jp