Signatures and hallmarks
A signature that looks fluid but has no consistent pen pressure, a silver hallmark whose letters do not exist.
Catawiki AI Checker
Is this Catawiki photo AI?
Upload the photos of a Catawiki lot and get an AI-signal score per photo — free, no account, nothing to install. Catawiki blocks automated checks, so you upload the photos yourself.
- Upload the lot photos as shown on Catawiki (screenshot or download)
- Max 12 photos per check, JPG/PNG/WebP
- Meant as a signal, not as legal proof
Upload Catawiki photos to start.
Recent checks
Stored on this device only; no photo or personal data is sent apart from the uploaded photos.
What the score can tell you.
The detector looks for patterns that are common in AI-generated or heavily edited images. It does not prove a seller did anything wrong — when in doubt, ask for extra photos or ask the seller directly.
- High score = elevated risk of AI-synthetic content
- Low score = no strong AI signals (still no guarantee it is "real")
- Use the score to ask further questions, not as a final verdict
Why AI photos on Catawiki are a problem
What goes wrong, and why the eye misses it.
In auctions the value sits in the detail: a signature, a hallmark, a patina. Those are exactly the details a generative model invents, and exactly what you are bidding on.
A generative model has no model of the world: it predicts what a photo of this kind of thing usually looks like. That makes AI images convincing at a distance and inconsistent in the detail — the opposite of a real photo, which is messy at a distance and holds up close. Anyone scrolling a list quickly sees the convincing version.
The checker inverts that order. Every one of the lot photos is scored separately for patterns associated with synthetic generation, so you know which photo is worth zooming into before you message a seller or place a bid.
Spotting it yourself: four things to check
Zoom all the way in and work through these four. Together they cost half a minute.
Wear
Real wear follows use: at the edges, near the handle, on the base. AI wear sits evenly across the whole object.
Symmetry
Vases, coins and watches are manufactured symmetrical. AI images are just off: dial indices sit unevenly, one handle of a vase sits higher than the other.
Certificates
Photos of appraisals and certificates of authenticity are unreadable at zoom in AI images. Ask for the document separately, as a PDF.
How to use the Catawiki AI Checker
- Paste the link or upload the photos. The page fetches the lot photos; uploading works too when the link is restricted.
- Read the score per photo. The average across a listing is not what matters; the photo that stands out is.
- Zoom into what the score points at. Seams, letters, reflections, edges.
- Ask one verification question. Ask via Catawiki for extra detail photos of signature, hallmark and base before bidding closes. An expert auction allows this.
A score starts a conversation, it does not end one. The detector cannot see who made a file, with which tool, or whether the seller is acting in good faith.
When it goes wrong
Catawiki: contact the auctioneer for the lot; lots are withdrawn when the imagery does not hold up.
Keep the listing URL and screenshots before you report: listings with generated imagery often disappear within a day, evidence included.
Frequently asked questions
Is the Catawiki AI Checker free?
Yes. No account, no daily limit and no payment method. The check runs on the same detector as the rest of this site.
Does a high score prove the Catawiki photo is AI?
No. The result is a warning signal, not proof of origin. A high score means the photo carries patterns common in generated or heavily edited imagery. Use it to ask sharper questions.
What does a low score mean?
That no strong AI signals were found. It is not a guarantee the photo is real: a compressed, cropped or forwarded photo loses signal. When in doubt, the follow-up question to the seller still stands.
Are my photos stored?
No. Images are processed to compute the score and are not used for model training by default. The history under the checker lives in your own browser only.
How accurate is the detector on Catawiki imagery?
Measured recall and false-warning rate are published with sample size and interval on the accuracy page. The newest generation of imagery is the weakest spot and that figure is stated separately.