CloudConverter

Protect PDF

Add a password to a PDF with strong AES-256 encryption, so only people with the password can open it.

Click to add files or drag and drop them here

PDF files · up to 10 files · 50 MB each

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How it works

1

Choose a PDF

Tap the box or drag one or more PDF files onto it, up to 50 MB each.

2

Set a password

Type the password twice. Use at least 8 characters with letters and numbers for real protection.

3

Download

Save the encrypted PDF. It asks for the password every time it is opened.

Bank statements, salary slips, ID copies, medical reports and contracts often travel by email and WhatsApp, where they can be forwarded or end up on the wrong device. Adding a password encrypts the PDF so that nobody can open it without the password, even if the file itself leaks. This tool uses AES-256, the strongest encryption PDF supports.

How the protection works

The whole content of the PDF is encrypted with AES-256. Every PDF reader (Adobe Acrobat, Chrome, Edge, Preview on Mac, phone apps) asks for the password before showing anything.

Send the password separately from the file, for example by phone or a different chat, so one leaked message is not enough to open it.

Your password is used once to encrypt the file and is never stored or logged.

Choose a strong password, and keep it

Short passwords such as a birth date can be guessed by cracking tools. Use 8 or more characters mixing letters, numbers and a symbol, or a phrase of several words.

There is no way to recover a forgotten password from an AES-256 PDF, so keep it somewhere safe. Keep an unprotected copy of the original if you might need it later.

Where this comes in handy

Financial documents

Protect bank statements, tax returns and salary slips before emailing them.

ID copies

Lock scans of your passport, CNIC or Aadhaar when sending them to an agent.

Medical reports

Share test results only with the people who should read them.

Business files

Send contracts, price sheets and HR documents securely.

Frequently asked questions

How do I put a password on a PDF for free?

Upload the PDF here, type a password twice and press Protect. Download the encrypted PDF.

How secure is it?

The file is encrypted with AES-256, the strongest standard PDF encryption. Security then depends on how strong your password is.

Will it open on phones?

Yes. Every modern PDF reader on Android, iPhone, Windows and Mac supports it and asks for the password.

Can I remove the password later?

Yes, with Unlock PDF, as long as you know the password.

Do you store my password?

No. It is used once to encrypt the file and then discarded together with the file.

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