100% ON-DEVICE · NO SERVERS

Share the file.
If it leaks, know exactly who.

You send one private photo to someone you trust. Weeks later it turns up in a WhatsApp group you were never in. Save that copy, drop it into PrivateMark, and it names exactly who you sent it to, in seconds, from an invisible watermark woven into their copy alone. No servers, no accounts; every step runs on your iPhone, iPad or Mac.

Download on the App Store See how it works

Free to try: protect 3 shares on us. Investigating a leak is always free.

PrivateMark - Catch the leaker. And hide photos in plain sight. | Product Hunt
📵
Files never leave your deviceNo uploads. No cloud processing. Ever.
👻
Invisible to everyoneThe shared copy looks like any other file.
🎯
Per-recipient attributionEvery copy is unique. Leaks trace to a name.

How it works

Three steps between you and never wondering again.

01 / PROTECT🛡️

Pick a file, name the recipient

Choose a photo or a document (PDF, Word or PowerPoint) and tell PrivateMark who it's for: "Maria", "Legal", "Board". A watermark unique to that copy is woven in invisibly, entirely on your device.

02 / SHARE💬

Send it anywhere

WhatsApp, iMessage, Mail, AirDrop: share the protected copy like any file. It looks identical. Only your private registry knows which copy went to whom.

03 / INVESTIGATE🔎

Found it somewhere? Get the name

If the file surfaces where it shouldn't, import the copy you found. PrivateMark reads the invisible mark and tells you, with statistical confidence, whose copy leaked.

Built to survive the real world

Leaked files get recompressed, screenshotted and cropped. The mark survives.

The watermark isn't metadata. It lives in the pixels themselves. Measured in our lab across real messaging pipelines:

99%
survives WhatsApp & iMessage recompression
97%
survives screenshots
99%
survives crops
~41 dB
PSNR, invisible to the eye

Lab-measured attribution rates on our test corpus; real-world results depend on how badly a copy is degraded. When the mark can't be read, PrivateMark still recognises it's your file via perceptual fingerprint.

Documents, not just photos

The board deck. The contract. The report. Trace those too.

PrivateMark protects PDF, Word and PowerPoint files with the same per-recipient mark, woven into three independent layers so a leak points back to one person even after the file is forwarded, re-exported, or its text copied and pasted.

LAYER 1🖼️

Every embedded image

Charts, logos and photos inside the document each carry the invisible mark, the same technology that survives screenshots and photos of a screen.

LAYER 2🔤

The text itself

An invisible code is woven into the words. It rides along even if someone copies the text out and pastes it into a brand-new document.

LAYER 3🗂️

The file's fingerprint

A keyed mark in the file's own metadata makes a forwarded copy attributable the instant it lands back in your hands.

Files stay fully editable and open normally in Word, PowerPoint and every PDF reader. Honest limit: a screenshot of a text-only document isn't attributable, but the forwarded file, and any screenshot containing a watermarked image, are.

New · Hidden Photo

Send a decoy. Only they see the real photo.

Share a picture everyone sees as an innocent cover. Your trusted contact opens it in PrivateMark and sees the photo you actually sent, protected by encryption only the two of you can open. Send it as a private file, or as a normal photo through any chat.

Know more → Is it safe?

Zero-trust by design

Private things should stay private. Including from us.

Pricing

Try the whole loop free. Go unlimited when it clicks.

Every plan includes the full engine: same watermark, same attribution. Investigating leaks is free forever, even if you never pay.

Monthly

$2.99
per month · after 3 free protected shares
  • ✓Unlimited protected shares
  • ✓Unlimited investigations
  • ✓iPhone, iPad & Mac
Get the app
Best value

Yearly

$9.99
per year · under $1 a month
  • ✓Unlimited protected shares
  • ✓Unlimited investigations
  • ✓iPhone, iPad & Mac
Get the app

Lifetime

$29.99$19.99
one-time purchase · launch offer until Aug 31
  • ✓Everything in Pro
  • ✓Pay once, never again
  • ✓All future updates
Get the app

Billed through the App Store. Prices in USD; local pricing may vary. Subscriptions renew unless cancelled at least 24 h before the period ends.

FAQ

Fair questions, straight answers.

Can people see the watermark?

No. The mark is spread across the pixels at an imperceptible level (~41 dB PSNR, well past the threshold of visibility). The shared file has a generic filename and clean metadata, so nothing reveals a file is protected.

Do my files get uploaded anywhere?

Never. There is no server: embedding and reading watermarks are done by a neural engine that runs on your device. The only outbound traffic in the entire app is anonymous, content-free analytics (which feature was used, never what it was used on).

What if the leaker screenshots the file instead of forwarding it?

Screenshots are one of the channels we engineered for: 97% of screenshots still attribute correctly in our lab tests. Recompression by WhatsApp or iMessage and cropping survive at ~99%.

What happens if the watermark can't be read?

PrivateMark is honest about confidence. If a copy is too degraded, it falls back to a perceptual fingerprint, telling you "this is your file" even when it can't name the recipient, and it will never guess: attributions come with statistical confidence, or not at all.

Is this legal to use?

Watermarking your own photos and documents before you share them is generally lawful: you're marking your own property. What you do with an attribution is up to you; PrivateMark just gives you the fact of whose copy it was.

Which devices does it run on?

iPhone and iPad (iOS 17+), plus a native Mac app. One purchase covers all of them, and your registry syncs privately through your own iCloud.

Available now

Your files deserve a paper trail.

Download on the App Store

iPhone · iPad · Mac. One purchase, all devices.