OpenAI Adds Invisible Watermarks to ChatGPT Text for EU Compliance

OpenAI will add invisible watermarks to eligible ChatGPT and Codex text in the EU within weeks to comply with the EU AI Act, with global API customers able to opt in. Anthropic has launched similar watermarks, though synonym substitution can defeat detection.

2026-10-11 ~ 2026-10-11 · 2 related posts

• OpenAI and Anthropic roll out invisible text watermarks — synonym swaps cut detection from 92% to 17% — lmoroney · 2026-10-11
• OpenAI to add invisible watermarks to ChatGPT text in the EU for AI Act compliance — lmoroney · 2026-10-11