Proof of ownership for any file

Watermark it. Seal it. Prove it's yours.

In plain English: a tamper-proof seal on every file you publish — verifiable by anyone, without us.

EpochCore watermarks, protects, captions, and verifies any file — entirely inside your browser. Patient scans, legal exhibits, unreleased footage: everything stays on your computer and is never uploaded. Anyone can check a file is genuine on the verify page.

HIPAA-safe by design Bank-grade protection Zero upload Works offline
One seal, any filePDFVIDEOX-RAYSRECORDSAUDIO
100%
In-browser
0 bytes
Ever uploaded
2x signed
Built to outlast future threats
Every file
Safety-checked before sealing
01 · How it works

Three steps. Nothing leaves the device.

Everything happens on your computer. Your file is opened, marked, and sealed locally — only a small, anonymous fingerprint is ever recorded, so regulated content never leaves your walls.

STEP 01

Mark

Add a visible logo plus a hidden, invisible watermark tied to you — one that stays put even after a file is re-saved, cropped, or re-shared.

STEP 02

Seal

Lock in a tamper-proof certificate of ownership, and optionally encrypt the file so only the people you choose can open it. The file itself stays on your machine.

STEP 03

Verify

Anyone can confirm a file is genuine and unchanged — or trace a stolen, re-uploaded clip back to you. Fakes and deepfakes simply don't pass.

Live · real seals · in your browser

Seal a PDF right now.

Drop any PDF to add a tamper-proof cover page and a one-of-a-kind seal — computed entirely on your device. Your file is never uploaded.

Drop a PDF to seal
or click to choose · up to 32 MB · your file never leaves your browser
Choose PDF to seal
Sealed via this page: 0
02 · Who it's for

Built for the content that can't leave the building.

If uploading to a cloud editor is a compliance violation, EpochCore is the only way to mark and prove your media — because it never uploads.

Healthcare · Imaging

Watermark X-rays and records without a HIPAA breach.

Protect X-rays, scans, and patient records with a tamper-proof certificate of ownership — entirely in your browser. Patient information never goes to a server, so there's nothing to upload, log, or breach. You can also lock each file so only named recipients can open it.

✓ EPOCHSEAL
study · chest-PA
owner · verified
privacy · local-only
Legal · Evidence

Chain-of-custody you can prove.

Seal exhibits and depositions with a dated certificate of ownership. Show an exhibit is unchanged since intake — without ever handing the evidence to an outside service.

Media · Entertainment

Embargoed footage, marked at the source.

Give each reviewer a copy with its own hidden watermark that stays intact even after re-saving — so any leak traces straight back to the source.

Creators · Social

Captioned, reframed, and provably yours.

Auto-caption, clip the best moments, reframe to 9:16, and export sealed. When a deepfake or repost surfaces, the invisible mark proves the original is yours.

03 · The EpochSeal difference

A deepfake can copy your face. It can't copy the seal.

Every file you create carries a hidden, one-of-a-kind mark and a tamper-proof certificate of ownership. A cloned voice or AI lookalike can't reproduce them — so the fake fails the check while your original passes. Real protection against AI copies, not just a logo in the corner.

05 · Security & compliance

Serious protection, in plain sight.

The seal isn't marketing — it's the same class of protection trusted to secure banking, running right on your device.

◆ Lock

Lock files to people

Encrypt any file so only the recipients you name can open it — built to stay secure even against tomorrow's threats. Works entirely offline.

◆ Sign

Tamper-proof certificate

Every file gets a dated certificate of ownership that can't be forged or altered — and that holds up as technology changes.

◆ Privacy

Your file never leaves

Only a small, anonymous fingerprint is ever recorded — never the file itself. Sensitive content stays on your computer, by design.

◆ Safety

Checked before it's sealed

Every file is automatically screened for hidden threats and disguised content right in your browser before anything is sealed.

▸ Ready when you are

Prove your work is yours — without uploading a thing.

Open the suite in your browser. No account, no install, no data leaves your device.