Google has opened its SynthID Detector to the public worldwide in English. Anyone can upload an image, video or audio file to synthid.com to check whether it carries an invisible AI watermark.

The tool detects watermarks from Google’s models and partners including OpenAI, NVIDIA and Kakao. Apple support is planned. Google DeepMind’s Pushmeet Kohli announced the October 7 expansion.

Google says it has watermarked more than 180 billion images and videos plus audio equivalent to 240,000 years. Built-in verification in Search, the Gemini app and Chrome now handles over a million requests a day.

But the site is explicit about limits: “This is not a general AI detector.” Media without a SynthID watermark will not be flagged even if it was made by AI, so context and source still matter.

The expansion makes SynthID one of the largest provenance systems in media history. But experts caution that watermarks can be weakened by cropping or re-encoding, so detector results should be treated as one signal among many when judging AI-made content.