For those asking what this is about: SynthID is Google's invisible watermarking technology for AI-generated content — images, audio, text, and video get a hidden watermark embedded at generation time (by tools like Gemini/Imagen), so their provenance can be verified later. A detector site checks whether a file carries that watermark. One honest note: SynthID exists so people can tell AI-generated media apart from real content, so tools around it are best used to verify your own files, not to disguise AI-made content as human-made — many platforms prohibit watermark stripping. Good share though, knowing how to check provenance is genuinely useful these days.