Is this photo real, or did a machine make it?
Drop an image in. SynthCheck takes the file apart — credentials, metadata, how it was encoded, what size it came out at — and shows you what it found. Then it tells you how much that evidence is actually worth.
No image handy? Run an example
Nothing is uploaded — the file is read on your device · No account, no limit, no catch · Works with the internet switched off
What it actually looks at
Two layers. The first reads what the file declares about itself. The second reads the shape of the file, which survives even when a social platform has scrubbed everything else.
- 1C2PA Content Credentials
- A signed record of where an image came from and every edit since, backed by Adobe, Microsoft, OpenAI, Google and the camera makers. When it is present, the question is settled.
- 2IPTC Digital Source Type
- One field in the metadata where the generator declares itself. The value trainedAlgorithmicMedia means fully synthetic; compositeWithTrainedAlgorithmicMedia means AI elements over real material. Midjourney and Meta both write it.
- 3Generator leftovers
- Stable Diffusion, ComfyUI, InvokeAI and Fooocus quietly save the whole prompt, the seed, the sampler and the model name into the file. You can read it back word for word. Nothing else on earth produces those fields.
- 4Fingerprints in the file
- When metadata is gone, the file still gives things away: output sizes only diffusion models produce, quantization tables no camera would write, coding modes cameras never use. Weak alone, telling together.
What this can and cannot prove
Every other detector shows you a confidence percentage. Ask where that number comes from and you will not get a straight answer. We would rather show you the evidence and let you judge it.
Solid ground
- Confirming AI origin when the generator labelled its own output
- Reading signed C2PA manifests and every action recorded inside
- Recovering prompts, seeds and model names left in the file
- Showing camera body, lens, exposure and GPS
- Spotting generator-preset dimensions and software encoders after metadata is gone
Out of reach
- SynthID. Google DeepMind's watermark lives in the pixels, not the metadata, and there is no public reader. Use Google's own SynthID Detector.
- A verdict from pixels alone. We do not run a classifier and we will not invent a percentage.
- Certificate validation. We show you the manifest; the official verifier checks the signing chain.
- Anything at all, sometimes. A screenshot of a screenshot carries no information, and no tool can change that.
The one thing worth remembering
A clean file is not a real photo. Metadata is trivial to remove — taking a screenshot does it by accident. Absence of an AI marker is never evidence that an image is authentic. It only means this particular file has nothing left to say.
Markers are strong evidence in one direction and no evidence at all in the other. Any tool that treats silence as innocence is selling you certainty it does not have.
Why this suddenly matters
Article 50 of the EU AI Act took effect on 2 August 2026. Providers of generative AI must mark synthetic output so machines can detect it, with penalties up to EUR 15 million or 3% of worldwide annual turnover.
The markers this tool reads are moving from a voluntary courtesy to a legal obligation, and the share of AI images that declare themselves is climbing fast. Systems already on the market before that date have until 2 December 2026 to comply with the machine-readable marking requirement, and content generated before 2 August 2026 needs no retroactive labelling.
Stripping those markers to pass synthetic media off as real runs against the transparency regime, and against the terms of service of every major model provider. This tool reads markers. It does not remove them.
Questions
Is my image uploaded anywhere?
No. Every byte is parsed by JavaScript inside your own browser tab. There is no backend, no storage, no logging. Want to verify that yourself? Turn off your internet and use the tool anyway — it still works. That is the easiest proof there is.
Can you detect SynthID from Google Gemini?
No, and be sceptical of anyone claiming otherwise. SynthID hides a statistical watermark in the pixels themselves and Google has not released a public reader. If a Gemini image still carries its C2PA manifest or IPTC tag, we will find it. If those were stripped, the SynthID watermark may still be sitting in the pixels, invisible to us. Google runs its own SynthID Detector for that.
I checked a photo and got Inconclusive. Is it broken?
No — that is the honest answer for that file. Instagram, Facebook, WhatsApp, Telegram, Discord and X all re-encode what you upload and throw away the metadata. Screenshots lose everything too. When that happens we fall back to reading the file's structure, which catches a lot of generated images, but not all of them. Try the original file rather than a version saved off social media and you will usually get much further.
Can the markers be faked?
In both directions, and we say so on every result. EXIF is plain text that can be copied from a genuine camera file onto a generated one, which is why camera evidence is reported as supporting rather than conclusive. C2PA manifests are cryptographically signed, so forging one convincingly is far harder — but verifying the signing certificate needs the official verifier, which we link to on every report.
Which formats work?
JPEG, PNG, WebP, AVIF, HEIC/HEIF and TIFF. JPEG and PNG get the deepest treatment, including compressed zTXt and iTXt chunks and full quantization table analysis. AVIF and HEIC get container parsing plus a raw marker sweep.
What does it cost, and what is the catch?
Nothing, and there isn't one. The site is paid for by advertising. Since no file ever leaves your device there is no server cost per check, so there is no reason to meter you, gate features or ask for an email address.