Google’s SynthID Detector is now open to everyone. This week Google opened public access to the tool at synthid.com, letting anyone upload an image, video or audio clip and check whether it carries the invisible SynthID watermark that Google and several partners embed in AI-generated media, according to TechCrunch and The Verge.
What the SynthID Detector checks
Google first gave the detector to a limited group of journalists, media professionals and researchers after showing it at Google I/O last year. The public version accepts a long list of formats, TechCrunch reported: JPG, PNG, WEBP, AVIF, HEIC, TIFF and GIF images; MP4, MOV and WEBM video; and WAV, MP3, OGG, FLAC, AAC and M4A audio.
The detector looks for SynthID, a watermarking system Google introduced in 2023 that hides a near-invisible marker inside generated content. Google says its Nano Banana, Veo and Lyria models, along with products such as Gemini, Flow, ProducerAI and Vids, stamp their output with it. That includes tools we covered when Google Vids added free 1080p AI video.
Which AI companies support SynthID
SynthID is no longer a Google-only signal. TechCrunch reported that OpenAI, NVIDIA and Kakao also support the watermark, and Apple is said to be adding support soon. OpenAI keeps its own verification site as well. Google has already built SynthID checks into the Gemini app and Chrome, and the company says people make about 1 million verification requests a day.
Engadget, in its coverage of the launch, noted the site is available globally in English. Google described the expansion on its official blog.
The limits of AI watermark detection
A clean result does not prove a file is human-made. The detector can only find the SynthID watermark, so content from tools that use other systems, or no watermark at all, can slip through. Microsoft and Meta run their own watermarking and verification standards, and TechCrunch pointed out that such tools often fail to flag content made by their own makers’ models. Cropping, re-recording and heavy editing can also weaken hidden marks.
That gap matters as synthetic voices and video get more convincing. Boston startups are working on the same problem from the audio side, as in our report on Modulate’s $25 million raise for voice deepfake detection.
Why the SynthID Detector matters for readers
For everyday users, the public site turns a behind-the-scenes standard into something you can actually check before sharing a viral clip. It is most useful as one signal among several: look at the source, look for the original upload and compare with trusted outlets. As more companies sign on, the share of AI media that can be verified this way should grow.
Sources: TechCrunch; The Verge; Engadget; Google.