Protect Your Document

Create cryptographic proof of existence without uploading your file to the server

How does it work?
Select your file
Processed in your browser, never uploaded to server
We seal the hash
We permanently anchor it on the Bitcoin blockchain
Download your proof
.ots file proving your document's existence
Create New Seal
Ej: "Contrato de arriendo marzo 2025"

Drag your file here

or click to select

100% private: file is processed in your browser and never sent to the server

This information is encrypted with your personal key. Only you can see it.

BTCSeal anchors your document's fingerprint (SHA-256 hash) on the Bitcoin blockchain, creating independently verifiable proofs of existence. Your document is never uploaded to the server, only its mathematical hash, guaranteeing total privacy.