Michael JohnsonGoogle has opened SynthID Detector to users worldwide. In its October 7, 2026 announcement, the company said the service is available in English and checks images, video, and audio files. Detector looks for the SynthID watermark—a mark Google embeds in AI-generated content. The result answers a specific question: whether this signal is detected in the file.
How to check a file
Open SynthID Detector, upload an image, video, or audio file, and start the check. Google announced that worldwide access in English began on October 7. The company had also described uploading a file and scanning it for SynthID in its original portal announcement. Google’s latest announcement did not specify upload size or duration limits.
Google says Detector is designed for content created with its own AI tools and those of partners including OpenAI, NVIDIA, and Kakao; Apple is named as a future partner. However, the check looks for a compatible SynthID mark, not for any content from every product made by these companies.
What SynthID scans
SynthID embeds digital watermarks directly into AI-generated images, video, audio, and text. In its description of SynthID technology, Google says that video marks can be placed in video segments and that the audio mark is imperceptible to listeners. The company designs the watermarks to withstand common changes: for images and video, these include cropping, filters, frame-rate changes, and compression; for audio, they include added noise, MP3 compression, and speed changes.
If Detector finds a mark, it may point to parts of the file where the system estimates SynthID is present. Google described highlighting likely areas in images and audio in its 2025 portal announcement. The new launch expanded access to the tool and added video and audio checks for a wider audience.
Google says that by October 7, 2026, it had marked more than 180 billion images and videos with SynthID, as well as audio content totaling 240,000 years in duration. These are the company’s own figures for the scale of its system’s use.
How to interpret the result
A positive result indicates that Detector found SynthID in the file or part of it. This can help associate the media with the watermarking system, but by itself it does not establish who created it, when it was made, or whether its content is accurate: those conclusions require separate information about provenance and context.
If no mark is found, the tool reports that it did not detect a SynthID signal in the file being checked. This check does not determine whether the media was created by a person or by another AI tool without this mark. Google’s documentation describes Detector as a portal for checking media with a SynthID watermark specifically.
Google announced a global launch in English, but did not specify pricing or plan terms in its announcement. Therefore, based on the published information, the service cannot be described as free. Detector’s practical role is to quickly check for one specific provenance signal; assessing a media item’s source and context remains a separate task.