OpenAI Rolls Out Text Watermarking for ChatGPT and Codex in the EU
OpenAI has launched an invisible, machine-readable text watermarking system called textGrain for ChatGPT and Codex, with an initial rollout limited to users in the European Union.
The watermarking technology embeds a detectable signal into AI-generated text that can be identified by specialized tools without altering the visible content. OpenAI claims textGrain "matched or exceeded" other approaches such as Google DeepMind's SynthID for text, which also serves as the foundation for watermarking Anthropic announced in August.
Both OpenAI and Anthropic implemented text watermarking in response to requirements under the EU's AI Act, which establishes transparency obligations for providers of general-purpose AI models. The legislation mandates certain technical measures to distinguish AI-generated content from human-created material.
OpenAI published benchmark data indicating that watermarked text performs comparably to unwatermarked output across standard evaluations. However, the company acknowledges that textGrain does not provide absolute certainty in detecting AI-generated content.
The staged EU-first deployment suggests a broader rollout may follow as other jurisdictions develop similar regulatory frameworks around AI transparency and content attribution.