Protect PDF – Add a Password

Upload your PDF and set a password; your file gets locked with AES-256. We never store your password anywhere.

  • PDF becomes Locked
  • Up to ⁦25 MB⁩
  • No sign-up
  • AES-256

11 Protect PDF

  1. 01 Pick
  2. 02 Process
  3. 03 Download

HTTPS · deleted after about 10 min

PDF

Selected file

Size: Ready

Ready. One click to go.

Live status

Uploading your file

Result

Locked.

0pages password-protected

That didn't work.

6–40 characters. Write it down: we don't store your password, so if you forget it, we can't open the file either.

Extra restrictions · optional

Programs that follow the rules, like Adobe Acrobat, respect these restrictions; some may ignore them. The password is the real protection.

  • No account, no cost.
  • We don't keep your password: if you forget it, we can't open the file either.
  • Your file is deleted about 10 minutes after processing.

Choose a PDF first

Stages

  1. Uploading your file
  2. Checking the file
  3. Encrypting the PDF
  4. Finishing touches

You stop waiting; the copy on the server deletes itself.

Download file

Self-destructs in 10:00

Then it's permanently deleted from the server. Download it now.

01

Why add a password to a PDF?

PDFs with personal or confidential information, such as payslips, medical reports, ID copies, contracts or customer lists, can easily end up in the wrong hands via email, cloud folders and messaging apps. A PDF with an opening password cannot be opened by anyone who doesn't know the password, so its contents stay protected even if the file goes to the wrong address.

The Dönüştür.net Protect PDF tool encrypts your file with AES-256, the strongest PDF encryption standard available today. If you like, you can also restrict printing, copying text and making changes. Your password is used only in our server's memory during this process; it is never saved anywhere, never written to log files and is discarded as soon as the process ends.

02

How to password-protect a PDF in 3 steps

  1. Upload your PDF: Drag your file into the area above or click to select it. Files can be up to 25 MB.

  2. Set your password: Type a password of 6 to 40 characters and enter it again to make sure you didn't mistype it. The eye icon lets you see what you typed. If you like, also tick the printing, copying and editing restrictions.

  3. Encrypt and download: Click “Protect PDF” and save your encrypted PDF with “Download file”. “protected” is added to the file name, so Payslip.pdf becomes Payslip_protected.pdf.

03

When is it useful?

  • Personal documents: Protecting scans of your ID card, passport, diploma or medical reports before sharing them.

  • Human resources: Sending payslips, employment contracts and performance reviews so that only the employee concerned can open them.

  • Accounting and legal: Sending financial statements, powers of attorney and court documents securely by email.

  • Customer data: Sharing PDFs that contain customer lists and quotes in line with data protection obligations such as the GDPR.

  • Cloud and USB drives: Preventing PDFs stored in cloud folders or on USB sticks from being read if the device is lost or stolen.

04

About encryption and security

  • AES-256 encryption: The PDF is protected with 256-bit AES encryption as defined in the ISO 32000-2 standard. Adobe Acrobat Reader, Chrome, Edge, Firefox, macOS Preview and current PDF apps open these files with the password.

  • Your password is not stored: The password arrives with your file over an encrypted connection, is used only in memory during processing and is never written to a database, a log file or disk. That also means that if you forget your password, we can't open the file either, so write it down somewhere safe.

  • A strong password: Choose a password of at least 10–12 characters that mixes letters, numbers and symbols and that you don't use anywhere else. Accented letters can be used too.

  • Restrictions: The printing, copying and editing restrictions are permission settings of the PDF standard; they are applied by programs that follow these rules, such as Adobe Acrobat, but some programs may ignore them. The real protection is the opening password.

  • PDFs that are already encrypted: A PDF that already has an opening or permissions password is not encrypted again. If you know the password, unlock it first with the Unlock PDF tool.

  • Content unchanged: Pages are not reprocessed; quality and file size stay almost the same. Up to 25 MB per file.

05

Privacy and automatic deletion

Your files are sent to our server over an encrypted HTTPS connection. The original file you upload is deleted as soon as processing finishes. The result file is kept only briefly so you can download it: an automatic clean-up job runs every minute and permanently deletes files older than 10 minutes. We therefore recommend downloading your result as soon as it is ready.

The download link only works for the user or browser session that started the job, and your files are never shared with other users. Our job log stores only details such as the file name, size and type of operation, never the file itself.

Read our Privacy Policy for details

06

Frequently Asked Questions

Is password-protecting a PDF free?

Yes. The tool is free and works without an account. Guests have a 24-hour usage allowance per tool; a free account lets you process more files.

Is my password stored on the server?

No. Your password exists in the server's memory only for the few seconds it takes to encrypt the PDF; it is never written to a database, log files or disk and is discarded as soon as the process ends. The encrypted PDF is also deleted from the server after about 10 minutes.

What happens if I forget my password?

Because we don't store your password, we can't open the file for you or recover the password. A PDF encrypted with AES-256 is practically impossible to open without the correct password. Keep the password in a password manager or another safe place, and keep the original unencrypted file as well.

Which programs can open the encrypted PDF?

Adobe Acrobat Reader, Google Chrome, Microsoft Edge, Mozilla Firefox, macOS Preview and current PDF apps on iPhone and Android open AES-256-encrypted PDFs. You just enter your password when you open the file.

What do the printing and copying restrictions do?

These restrictions are meant to stop people who can open the PDF from printing it, copying its text or changing it. Programs that follow the rules, such as Adobe Acrobat, apply them; since some programs may ignore them, the real protection comes from the opening password.

Can I remove the password later?

Yes. If you know the password, you can create an unprotected copy of the file with the Unlock PDF tool.

What kind of password should I choose?

Choose a password of at least 10–12 characters with upper- and lower-case letters, numbers and symbols, and nothing guessable like a birth date or a name. Share the password through a separate channel, such as a phone call or a text message, not in the email you send the file with.