Google is making its AI detection tool, SynthID Detector, available to all users starting today.
SynthID has been around for some time. Google uses it to watermark outputs generated by its AI systems, making it easier for end users to verify whether an image, audio, or video was created by Google's AI tools or a SynthID partner like OpenAI, Nvidia, and Kakao.
An early version of the SynthID Detector was made available to journalists, media professionals, and researchers via a waitlist last year. Now, it’s open for anyone; just sign in with a Google, Apple, or OpenAI account. Apple will join the program soon, after which all audio, video, and images generated by Apple Intelligence may also get flagged by the detector. For now, it can catch outputs from ChatGPT and Gemini.
I gave the SynthID Detector a quick try by up a kitchen redesign mockup I had recently generated using ChatGPT. It correctly flagged the source, both when I uploaded the output and a screenshot of the same.
“The watermark doesn’t change the image or video quality,” Google says. "It’s added the moment content is created, and designed to stand up to modifications like cropping, adding filters, changing frame rates, or lossy compression.”
The detector’s terms of use suggest that Google will store a digital signature of your media for 24 hours to enforce daily usage quotas and “defend the service against automated attacks.” Google adds that it deletes the signatures automatically after 24 hours.
So far, Google has watermarked over 180 billion images and videos, as well as over 240,000 hours of audio content. Microsoft also watermarks its AI audio, video, and image outputs, while Meta has its own AI image detector.
As far as AI text detection is concerned, there are several third-party options available, while OpenAI said earlier this week that it would begin watermarking text generated by ChatGPT and Codex in the EU over the coming weeks. Anthropic did the same in August.
Disclosure: Ziff Davis, PCMag's parent company, filed a lawsuit against OpenAI in April 2025, alleging it infringed Ziff Davis copyrights in training and operating its AI systems.