Gemini and SynthID

Google DeepMind invented the SynthID-Text technique and has been watermarking Gemini's text output since 2024 — considerably earlier than most coverage of the Claude announcement acknowledges.

SynthID also covers Imagen images, Veo video and Lyria audio including the NotebookLM audio overview feature. Google's public SynthID Detector portal accepts image, video and audio, but not text, and remains limited-access with a waitlist for journalists and researchers.