Docomint

Proteger um PDF com senha

Adicione uma senha a um PDF (AES-128) para que não possa ser aberto sem ela, totalmente no seu navegador.

🔒 Processed on your device

Drop your PDF here

or choose a file from your device

What is a Proteger um PDF com senha?

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 um PDF com senha

  1. Add a PDF file
  2. Set a password
  3. 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 um PDF com senha

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 um PDF com senha 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.

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