Google on Oct. 7 opened its SynthID Detector to everyone, at synthid.com, in English and worldwide. AI-made pictures, video and sound are getting harder to tell apart from real ones. People upload an image, a video or an audio clip, and the site says whether it carries SynthID, Google's watermark for AI: a hidden signal an AI tool weaves into an image, video or audio clip as it makes it, which software can spot but people cannot see or hear. Until now the detector, first released in an early version last year, was meant for journalists and other media professionals.
The site checks for the mark from Google's own AI tools and from partners that have adopted it, which Google names as OpenAI, NVIDIA and Kakao, with Apple coming soon. Google says it has put the mark on more than 180 billion images and videos and on 240,000 years of audio. Similar checks already built into Google Search, the Gemini app and Chrome now handle more than 1 million requests a day, the company says.
According to a news report, people must sign in to use it, and Google puts the daily limit at about 10 checks. Google's privacy notice says uploaded files are deleted as soon as the result comes back, while a short digital record of each file is kept for 24 hours to enforce that limit. Images, videos and audio are accepted in common formats, including JPG, PNG, MP4, MOV and MP3. For video and audio, the site points to the stretches that carry the mark.
The site itself warns that it is not a general AI detector. A positive result means the file was likely made or edited with one of those companies' AI tools. It can only find the mark from companies that use it, so a file made with another company's tool, or with an older model from before a partner adopted the mark, can come back as not detected. Heavy editing or compression can weaken the signal, Google says, and someone who tries many changes may find one that hides it. In very rare cases the tool can also flag a file that carries no mark, so Google advises gathering other evidence before deciding.
Google has not said when Apple's mark will be added or which Apple products will carry it. The site works only in English for now.