Google opened SynthID Detector to the public worldwide in English on Oct. 7, 2026. The web tool checks images, video, and audio for SynthID, Google’s digital watermark: an embedded signal designed to be imperceptible to people but detectable by systems that look for it. It is a check for that signal, not a universal test for AI-generated media.
That distinction matters when you’re trying to understand where a file came from. The result can tell you whether the tool found a supported SynthID signal; it cannot settle every question about a file’s origin.
What SynthID Detector checks
Google says SynthID Detector checks images, video, and audio. The company named OpenAI, NVIDIA, and Kakao as partners whose AI media the tool can check, and said Apple would join later. The check is for SynthID signals, not a blanket verdict on everything produced by those services or by other AI tools.
SynthID works by embedding a digital watermark in generated media. Unlike a visible logo, the signal is designed to be imperceptible to a viewer while remaining detectable by the system. Google DeepMind’s earlier explainer introduces the watermarking approach and its limits as one part of addressing misinformation.
What a positive or negative result means
A positive result means the detector found a supported SynthID signal in the checked media. It does not, by itself, tell you whether the content is accurate or trustworthy.
A negative result means the tool did not find a supported SynthID signal. It does not prove that a person made the file: media without a detectable SynthID signal can still have been generated or edited with AI.
That’s the practical boundary. SynthID Detector can help identify media carrying the watermark it recognizes, but a check for one signal is not a universal AI detector.
The scale Google reports for SynthID
Google reported that SynthID had watermarked more than 180 billion images and videos and 240,000 years of audio content. The company also said verification features in Search, the Gemini app, and Chrome handle more than 1 million requests a day.
