Send personal documents
Protect payslips, tax notices or ID documents before emailing them.
Password protect a PDF
Encrypt a PDF with AES-256 and an open password: without it, the document can no longer be opened. Encryption runs locally in your browser, with no upload.
- Export
Your files are processed locally in your browser and are never sent to our servers.
Drop your file here
Recommended size: up to 100 MB
The password will be required to open the PDF.
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How does this tool work?
Password-protecting a PDF encrypts the document: without the password, it can no longer be opened or read. It is the precaution to take before emailing a payslip, a medical file, a contract or a statement, especially if the message may be forwarded or the attachment intercepted. Encryption is applied in your browser; neither the document nor the password is transmitted.
The tool relies on qpdf, a reference library for handling PDFs, compiled to WebAssembly so it runs in the page. The document is encrypted with the AES algorithm and a 256-bit key, the strongest method defined by the PDF 2.0 standard (ISO 32000-2).
The password you enter becomes both the open password and the owner password. It is asked for twice to avoid a typo that would lock you out of the file. The resulting PDF opens normally in all recent readers (Acrobat, browsers, built-in system viewers), which then ask for the password.
The strength of the protection depends mostly on the password: AES-256 makes direct attacks on the encryption unrealistic, but a short or common password can be guessed by trial and error. Send it through a different channel from the document, for example by text message if the PDF goes by email.
How to use this tool
Import the PDF
Choose the document to protect; it stays on your device.
Enter the password twice
Both entries must match; a message warns you otherwise.
Download the encrypted version
The protected file will ask for this password every time it is opened. Test it before sending.
Use cases
Share a sensitive business document
Encrypt a quote, a contract or a confidential report intended for a client.
Store files on shared media
Keep private documents on a USB stick or shared cloud without leaving them readable by everyone.
Examples
A payslip to send
A passphrase of several words with digits and a symbol holds up far better than a 6-letter word. The password is then given to the recipient by phone, never in the same email as the file.
Input
payslip-march.pdf, password “Moon-Orchard-73!” entered twiceResult
PDF encrypted with AES-256 that asks for the password when openedTips and best practices
- Use at least 12 characters, ideally a passphrase; Bethemesh offers a password generator in the Security category.
- Keep the password in a password manager: there is no way to recover an encrypted PDF whose password is forgotten.
- To only block printing or copying without preventing opening, use Change PDF permissions instead.
- Do other transformations (merging, compressing, watermarking) before protecting: an encrypted PDF must be unlocked to be edited again.
Sources and references
Frequently asked questions
Which encryption is used?
AES with a 256-bit key, applied by qpdf. It is the highest level defined by the PDF standard and is supported by current readers.
What happens if I forget the password?
The document can no longer be opened. Bethemesh keeps neither the file nor the password and therefore cannot recover it.
Does the recipient need special software?
No. Common PDF readers, including those built into browsers, can open an AES-256 encrypted PDF once the password is entered.
Is the password sent to Bethemesh?
No. It is only used for the encryption performed in your browser and is neither stored nor transmitted.
Can I remove the protection later?
Yes, with Unlock a PDF and the password you chose.
Does the protection also prevent printing?
No. Once the document is opened with the password, every action is allowed. To restrict printing or copying, use Change PDF permissions.
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