Product4 publishersIndependently confirmed2 min readPublished
SynthID.com lets anyone test a file for watermarks from Google, OpenAI, Nvidia and Kakao
Google opened SynthID.com to anyone, checking images, video and audio for OpenAI, Nvidia and Kakao watermarks as well as its own. That speeds up flagging partner-made media but cannot vouch for files from outside the SynthID group.
The Product Desk · Product desk
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What happened
- Before the launch, anyone outside Google's trusted tester program could check a file for SynthID only by asking Gemini.
- Select journalists, media professionals and researchers had been testing the tool since Google I/O last year, and Google opened it to everyone on Tuesday.
- The public site returns only a message saying whether SynthID was used to produce or edit a file, without the internal tool's highlighting of watermarked regions.
- It accepts 20 listed file types across images, video and audio, including HEIC and AVIF photos, MOV video and FLAC audio.
- Apple is due to add SynthID support soon, according to Google.
Compiled by The Product DeskSomething wrong?How this is made
Why it matters
- capability A reviewer no longer needs to know which vendor made a file before picking a detector, because one upload checks all the partners' watermarks.
- cost One message covers both generated and edited media, so anyone who needs to know which part of a photo was changed still has to find that out another way.
- exposure Anyone passing off partner-made images as real now faces a check that any recipient can run on a public website, with no need to go through Gemini.
Take a ChatGPT image that a reviewer ran through Google's old detector. The file carried SynthID, and the detector still would not flag it, because it read only Google's own version of the watermark [9]. Asking Gemini instead had its own problem. Ars Technica found the model's answers could be confusing to someone who just wanted a yes or no [8].
In TechCrunch's summary, the pitch is a site that lets anyone verify whether a piece of media is AI-generated [5]. The site checks for SynthID, an invisible signal written into the pixels of images and video and into the waveform of audio [12]. Google stamps it on output from its Nano Banana, Veo and Lyria models and from tools including Gemini, Flow, ProducerAI and Vids [16]. By Google's count, Gemini alone has put it into more than 180 billion images and videos and 240,000 years of audio [11].
A negative result covers much less ground. Microsoft and Meta have their own watermarking standards [19], so output from their models is outside what SynthID.com looks for. OpenAI, a SynthID partner, also keeps its own checking site [2][17]. TechCrunch noted that these tools are not infallible and often fail to identify content made by their makers' own models [21].
Google has built SynthID checks into the Gemini app and Chrome, and says people make 1 million verification requests a day [18]. Neither report includes a figure for how often those checks are right.
For a team adding this to a review queue on Monday, the useful grid has two axes. One is whether the decision needs to show a file is AI-made or show that it is real. The other is whether the site said yes or no. A yes on a file you suspect is AI-made is a flag you can act on, as long as the file came from a partner's model. A no on that same file settles little. If the decision is about clearing a file as real, the site can only rule a file out, and only with a yes.
I'd put SynthID.com at the front of any queue that flags content as AI-made and keep it out of any step that approves content as authentic, since a no from the site leaves the reviewer with the same work they had before the upload.
What to watch
- Whether Microsoft or Meta join SynthID, or Google adds their watermark standards to the site, which would widen what a negative result covers.
- Whether Apple's SynthID support ships and its watermark starts registering in SynthID.com checks.
- Whether OpenAI keeps its separate checking site now that Google's public detector reads its watermark too.