PDFPixo

Lock PDF with password

Protect a PDF with strong AES-256 encryption.

Also called: lock PDF, add password to PDF.

Add a password to a PDF before you share it. Only people who know the password can open it.

Lock a PDF with a password

This tool adds a password to a PDF, so nobody can open it without that password. Use it before you email bank statements, salary slips, ID copies, medical reports, contracts or any document with private details. Even if the email or WhatsApp message reaches the wrong person, the file stays closed.

Strong encryption

The PDF is locked with AES-256 encryption, the strongest standard used by PDF readers. Text, links and forms inside the PDF are kept exactly as they were; only opening the file now needs the password. The locked PDF opens in every common reader, such as Adobe Reader, Chrome, phone file apps and Microsoft Edge.

Choosing a password

The password must have at least 4 characters, but longer is much safer. Use a mix of letters and numbers that is easy for the receiver to type, for example a word plus a year. Type it twice so a typing mistake does not lock you out. Avoid your mobile number or date of birth when the document is very sensitive.

Share the password separately

Never send the password in the same email as the PDF. Send it by SMS, a phone call or another app. That way, a person who sees only one of the two cannot open the file.

If you forget the password

Keep the password safe. If it is forgotten, the file cannot be opened by anyone, including PDFPixo, because the encryption has no back door. Always keep your original unlocked copy on your own device.

Already locked?

If the PDF already has a password, the tool asks you to unlock it first with the remove password tool, then lock it again with the new password.

Common uses

Send salary slips to employees, share a bank statement with a loan agent, email ID proofs for a job, send medical reports to a doctor, or keep tax files safe on a shared computer.

Protect, then share

A good order for private documents is: hide numbers you do not need to share, add a watermark that states the purpose, compress if there is a size limit, and lock the PDF with a password last. Locking last keeps every other step easy, because most tools need an unlocked file.

An example

To email a salary slip to a bank, lock it with a password such as the first four letters of your name and your birth year, send the PDF by email, and tell the bank officer the password on a phone call.

Private by design

Your file is processed inside your own browser. It is never uploaded to a server, and nothing is kept after you close the page. There is no sign-up, no watermark and no daily limit. For private documents such as ID cards, this matters more than anything else.

How to use it

  1. Choose the PDF Pick the document to protect.
  2. Type a password At least 4 characters; longer is safer.
  3. Confirm it Type the same password again.
  4. Lock and download Share the password separately.

Why choose PDFPixo for this tool

  • AES-256 The strongest standard PDF encryption.
  • Nothing changes inside Text, links and forms are kept.
  • Opens everywhere Works in all common PDF readers.
  • Private and free The file and password never leave your device.

Frequently asked questions

How do I put a password on a PDF?
Choose the PDF, type the password twice and press the button.
How strong is the lock?
It uses AES-256 encryption.
What if I forget the password?
Nobody can open the file. Keep your original copy.
Will the receiver need special software?
No. Any common PDF reader asks for the password.
Is my password sent anywhere?
No. The file is locked inside your browser.

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