AI Matters
Why it matters
Anthropic adds invisible watermarks to text processed by Claude
Ars Technica Claude's new Scarlet Letter watermark is invisible—for now
Anthropic introduced an invisible watermarking system that flags any text processed or edited by its Claude AI model.
Why it matters
Users who use Claude to edit or write professional or academic work may face detection issues due to invisible watermarks.
Latest brief · Oct 19, 2026