OpenAI’s EU text watermark makes provenance detectable but keeps verification gated
The compliance signal is arriving before a public detector—and it degrades quickly when text is edited.
OpenAI has made its textGrain watermark optional for selected API models worldwide and says eligible ChatGPT and Codex output in the EU will receive it over the coming weeks. Detector access will initially be limited to approved researchers and expert organizations, while OpenAI reports that replacing 10% of words with synonyms cut detection from about 92% to 66% in one evaluation. Publishers and platforms gain a machine-readable origin signal, but its practical value depends on provider-controlled detector access and a mark that ordinary editing can substantially weaken.