On July 30, 2026, Google turned on an AI image generator inside Google Earth's web app: zoom into any point on the map, type a prompt, and get a photorealistic scene rendered onto that location's own satellite and terrain data. By July 31 the feature was gone. Screenshots had already spread of a fabricated blast crater over a real Los Angeles address and a staged protest outside Google's own Mountain View headquarters — neither event real, both built on genuine reference imagery of a genuine place. The full rollback happened in under 24 hours. Every image the tool produced carried an invisible Google SynthID watermark the entire time — nobody checked before sharing, because almost nobody knows the check exists. That's the actual gap this guide closes: not spotting a fake by eye, which gets harder every month, but knowing which real systems can tell you something concrete, and in what order to check them.
Two different systems, and who's actually in them
Two unrelated mechanisms currently do this work, and knowing which one you're looking for changes where you check. Content Credentials, built on the C2PA standard, are a cryptographically signed manifest embedded in the file itself — a record of what tool made it, whether generative AI was involved, and what's been done to it since. The coalition's steering committee includes Adobe, Microsoft, Meta, Sony, the BBC, Google, and OpenAI, which has embedded this metadata in every DALL·E 3 and ChatGPT image since February 6, 2024. SynthID is a separate thing entirely: an invisible pattern Google embeds directly into the pixels — and, separately, the audio — of AI-generated content at the moment of creation, built to survive cropping, filters, and recompression in a way file metadata cannot. Since a May 2026 partnership, OpenAI's own image outputs carry both, layered on top of each other. Anthropic takes a third approach again: Claude's generated images and code files get signed C2PA metadata like OpenAI's, but Claude's generated *text* gets an entirely different, invisible pattern of its own. There is no single universal watermark — only a handful of lab-specific systems that happen to overlap on images.
Check an image in this order
- Download the actual image rather than working from a screenshot, a social-media repost, or a pasted-in copy. Both C2PA metadata and, to a lesser extent, SynthID's watermark can be damaged or destroyed by a re-save.
- Open verify.contentauthenticity.org and drop the file in. If a manifest exists, it names the generating tool and shows what's been done to the file since.
- Upload the file to the Gemini app and ask whether it was created or altered by Google AI, or use Chrome's right-click "Was this generated with AI?" option if you're viewing it in-browser.
- Search Google Images or TinEye for the exact file. If the same image already exists online, attached to a different, older, real story, that settles it regardless of what any watermark check returned.
- "A signed manifest names Google's Imagen" is a fact. "No watermark, so it's probably real" is a guess dressed as a finding.
Which of those five steps to start on depends on what you're actually holding — a link, a download, or a screenshot someone already sent you.
Start where the evidence still exists
The two mechanisms, side by side
C2PA and SynthID answer different questions
| C2PA / Content Credentials signed file metadata | SynthID pixel-level watermark | Reverse image search prior-publication check | |
|---|---|---|---|
| What it actually checks | A manifest embedded in the file, naming the tool and edit history | A statistical pattern embedded in the pixels or audio at creation | Whether this exact image has a prior, dated appearance online |
| Survives a screenshot or re-save | No — screenshotting and most re-saves strip it | Often, by design — built to survive cropping and recompression | Not applicable — works from the pixels, not a file's history |
| Where to check it | verify.contentauthenticity.org | The Gemini app, or Chrome's right-click check | Google Images or TinEye |
| What a clean result actually proves | That specific tool was involved, if the manifest is present and unaltered | That Google's (or OpenAI's) generator was involved, if a match is found | That this image, or a close match, existed before now |
None of these three replace judgment — they narrow it. A signed C2PA manifest naming a real generator is about as strong as this kind of evidence gets; a SynthID hit is nearly as strong for the labs it covers; a reverse-image match settles the question outright by proving the image already existed as something else. But all three can come back with nothing, and "nothing" is not the same finding as "clean." The apps generating nudify deepfakes that San Francisco ordered off the app stores in July 2026 don't run through OpenAI's or Google's pipelines, and their output carries none of these signals — which is exactly why the absence of a watermark can never be read as reassurance.
Where this check breaks
Five ways this check gets called done when it isn't
None of this makes spotting an AI image effortless — it makes it checkable, which is the more honest goal. The same discipline applies one level up the stack, on claims rather than pictures: our guide to catching an AI assistant when it's making things up is the text-side version of this same habit, and the dictionary has short entries for every term used here — manifest, watermark, provenance — if any of it needs unpacking further.
- Check for a signed C2PA Content Credentials manifest first — it names the generating tool directly.
- Google's SynthID watermark survives cropping and compression; check it via Gemini or Chrome's right-click tool.
- A screenshot or repost strips the file's metadata before you ever see it — get the original file.
- OpenAI's images have carried C2PA metadata since February 2024; SynthID now covers its images too.
- Caveat: no watermark found doesn't mean a photo is real — it only means this check found nothing.