DocomintProteger un PDF con contraseña
Añade una contraseña a un PDF (AES-128) para que no se pueda abrir sin ella, completamente en tu navegador.
Drop your PDF here
or choose a file from your device
What is a Proteger un PDF con contraseña?
Password-protecting a PDF is the standard way to keep a document readable only by its intended recipient in transit — tax documents, contracts, or medical records sent by email, where anyone who intercepts the message shouldn't be able to open the file without a password shared separately.
How to use the Proteger un PDF con contraseña
- Add a PDF file
- Set a password
- Download the password-protected PDF
Example
Protecting a PDF with the password "Q7#mx2Lp" and sending that password in a separate text message rather than the same email means the file stays unreadable to anyone who only gets the attachment.
Why use Proteger un PDF con contraseña
Real AES-128 encryption
The same standard security handler Adobe Acrobat and every major PDF reader recognize — not a proprietary lock.
Nothing uploaded
Your PDF is encrypted locally in this browser via the Web Crypto API; the file and the password you set never leave your device.
One password, full protection
The password required to open the file also governs the whole document — no confusing split between an owner and a user password.
What can you create?
Email a sensitive document
Password-protect a tax form or medical record before attaching it, then share the password through a separate channel.
Restrict a file before archiving
Lock a contract or financial record before it goes into shared or long-term storage.
Add a layer before handing off a device
Protect a personal PDF before it's stored somewhere other people can reach the file itself.
Frequently asked questions
Is my PDF uploaded anywhere?
No — Proteger un PDF con contraseña runs entirely in your browser using JavaScript/WebAssembly. Your PDF is never sent to a server.
Is there a file size limit?
Free use covers files up to 100MB per file; signing up for Pro raises that to 500MB.
What encryption does the password protection actually use?
AES-128 (revision 4), a widely supported standard recognized by Adobe Acrobat and most other PDF readers — not a proprietary or weaker scheme.
Can I let people view the PDF without a password but block printing or editing?
No — this sets a single open password required to view the file at all. Separate owner-permission passwords that leave viewing open while restricting printing or editing aren't currently supported.
What happens if I forget the password I just set?
There's no recovery — write it down somewhere safe before you close the tab, because a forgotten password on a protected PDF can't be recovered by this tool or anyone else without brute-forcing it.