Google rolls out improved SynthID AI content detector, now available globally

Google has announced that its SynthID detector now supports watermarks from all of its partners, and that it is available for anyone to use on a new dedicated website, SynthID.com, starting today. SynthID is an invisible signal encoded in the pixels of AI-generated images and videos and in the waveform of AI audio.

Until now, checking for SynthID from outside Google's trusted tester program meant asking Gemini, which Google describes as clunky and sometimes confusing when a simple yes or no was wanted. The previous detector also only checked for Google's version of SynthID, so content such as ChatGPT images carrying SynthID would not be flagged. Google says the expanded detector supports the distinct watermarks of all its SynthID partners, including OpenAI, Nvidia, Kakao, and soon Apple.

According to Google, Gemini alone has integrated SynthID with over 180 billion images and videos, plus 240,000 years of audio. The website will not provide as much information as the internal tool, which highlighted regions of an image that showed SynthID pixels; instead, users get a message telling them whether SynthID was used to produce or edit the media.

A login is required, with support for Google, OpenAI, and Apple accounts, and Google says each user gets a daily usage quota of approximately 10 image, video, and audio checks. Google engineers have told Ars that limiting access is necessary to prevent people from using the checks to develop SynthID removal tools. The exact number may vary, as the system may lock users out sooner if they check multiple very similar images.

The tool will carry a disclaimer noting that not all AI content is covered. Some model providers use different watermarking technology, such as Meta, others use no watermarks, and open-weight models run on personal hardware may produce AI content without even simple metadata labeling. Google's Pixel phones are among the few devices using cryptographic technologies like C2PA to label real media at creation.