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Protect PDF

Add a password to a PDF. AES-256 encryption. Free online PDF password protector.

⚡Runs on our server. Server-side: qpdf --encrypt with AES-256. The file is processed in an isolated temp directory and deleted immediately after.

About Protect PDF · বিস্তারিত

Protect PDF encrypts your PDF with 256-bit AES using qpdf, so the file asks for your password before anyone can open it. The password must be at least 4 characters, and the same password is set as both the open password and the owner password.

Salary slips, bank statements, signed contracts and copies of NID or passport pages are often sent by email or messenger. Once a file leaves your hands it can be forwarded anywhere, so a password is a simple extra layer: without it, the PDF will not open in Adobe Reader, a browser or a phone viewer.

On our server the file is encrypted with qpdf at 256-bit AES, the strongest standard option in the PDF format. Because one password is used for both opening and owner rights, anyone who knows it can open the file and also print, copy or edit it. The tool does not set separate permission limits.

How to use it · কীভাবে ব্যবহার করবেন

  1. Choose the PDF

    Select the document you want to lock.

  2. Type a password

    Use at least 4 characters. A longer phrase mixing words and numbers is much harder to guess.

  3. Run Protect PDF

    The file is sent to our server, encrypted, and returned.

  4. Test it, then share

    Open the downloaded file once to confirm it asks for the password. Send the password through a different channel from the file, for example by phone call or SMS.

When it helps · কখন কাজে লাগে

Payslips and HR letters
An HR team can lock each employee's salary statement before emailing it, so a wrong address does not expose the figures.
Identity documents for visa or bank work
When an agent asks for scanned passport, NID or bank statement pages, a password keeps the PDF closed if the email is forwarded further.
Client reports and quotations
Freelancers and small firms can send pricing or audit reports that only the named client can open.

What you get

  • 256-bit AES encryption, applied by qpdf
  • Minimum password length of 4 characters
  • Opening the file requires the password in any standard PDF reader
  • Pages, layout and text are unchanged apart from the encryption
  • PDF files up to 100 MB
  • Free, no account

বাংলায়: PDF-এ পাসওয়ার্ড দেওয়া

বেতনের স্লিপ, ব্যাংক স্টেটমেন্ট, চুক্তিপত্র বা NID-পাসপোর্টের স্ক্যান PDF ইমেইলে পাঠানোর আগে পাসওয়ার্ড দিয়ে লক করে নিতে পারেন। এই টুল qpdf দিয়ে ২৫৬-বিট AES এনক্রিপশন করে, তাই পাসওয়ার্ড ছাড়া ফাইলটা খুলবে না। পাসওয়ার্ড কমপক্ষে ৪ অক্ষরের হতে হবে, তবে লম্বা পাসওয়ার্ড অনেক বেশি নিরাপদ। ফাইল আমাদের সার্ভারে এনক্রিপ্ট হয়, তারপর অস্থায়ী কপি মুছে ফেলা হয়।

পাসওয়ার্ড ভুলে গেলে কী হবে?

আমরা পাসওয়ার্ড রাখি না, তাই খুলে দেওয়া সম্ভব না। আসল ফাইলটা নিরাপদে রেখে দিন।

পাসওয়ার্ড কীভাবে পাঠাব?

ফাইল যেভাবে পাঠাচ্ছেন সেভাবে না, অন্য মাধ্যমে দিন, যেমন ফোনে বলে বা আলাদা SMS-এ।

প্রিন্ট বা কপি বন্ধ করা যাবে?

না। যার কাছে পাসওয়ার্ড আছে সে খুলে প্রিন্ট আর কপি দুটোই করতে পারবে।

Questions people ask · প্রশ্ন ও উত্তর

What encryption does this use?

AES with a 256-bit key, set by the open-source tool qpdf (its "256" encryption mode). Current versions of Adobe Reader, Chrome, Edge, Firefox and phone PDF viewers can open these files when the password is entered.

Can I stop people from printing or copying the PDF?

Not with this tool. It sets the same password for opening and for owner rights, so anyone with the password gets full access. If you need printing blocked, you would need a tool that sets separate permission flags, and even those are easy to bypass.

Is my file safe on your server?

The PDF and the password are sent over HTTPS to our server, encrypted in a temporary folder, and that temporary copy is deleted right after the protected file is sent back. We do not keep the password.

I forgot the password. Can you open it?

No. The file is encrypted with your password and we do not store it, so there is no way for us to recover it. Keep the original unprotected copy somewhere safe.

How strong should my password be?

The tool accepts 4 characters, but a short password can be guessed by software. For anything sensitive, use 10 or more characters, for example three unrelated words with a number.

Does protecting a PDF make it bigger?

Usually only by a few kilobytes. The content is the same, just encrypted.

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