[ENCRYPT PDF ONLINE]

Encrypt a PDF without handing it to a stranger's server first.

Most "encrypt PDF online" services upload your document, process it on their servers, and give you a download link. For a contract, a medical record or a bank statement, that means the exact document you were trying to protect has been sitting on someone else's machine — usually the thing you were trying to avoid.

This tool encrypts the file in your browser. The PDF never leaves your device, and there is no size limit or watermark.

ENCRYPT_FILE_ONLINE_v1.0.0
🔒 [ENCRYPT] 🔓 [DECRYPT]

[1] SELECT FILE

[2] CHOOSE ENCRYPTION ALGORITHM

[4] ENCRYPT FILE

[TWO WAYS TO PROTECT A PDF]

As with Word documents, "encrypting a PDF" covers two genuinely different things. Which you want depends on how the recipient will open it.

PDF password protection (inside the format)

The reader prompts for a password and then displays the document. Convenient, because any PDF reader handles it. Set it in Acrobat, or free of charge in LibreOffice Draw via File → Export as PDF → Security. This tool cannot add or remove that kind of password.

File encryption (this tool)

The whole PDF becomes an opaque .enc file. Nobody can tell it is a PDF, what it is called, or how large the original was. Stronger, and the right choice for transmission and storage — the recipient decrypts it here before opening.

[CHOOSING BETWEEN THEM]

You want to… Use
Email a document that must open in any PDF readerPDF password (Acrobat / LibreOffice)
Store it in cloud backup where nobody should see itFile encryption (this tool)
Hide even the filename and document typeFile encryption
Use a random 256-bit key rather than a passwordFile encryption
Stop recipients printing or copying textPDF permissions — but see the warning below

A caution on PDF permissions. "Owner passwords" that restrict printing, copying or editing while still letting anyone open the document are advisory. The content is not protected from a determined reader, and many tools ignore the restriction entirely. Only a password required to open the file actually encrypts it.

[COMMON USES]

  • Contracts and legal documents sent to a counterparty or held in shared storage
  • Medical records and test results, where the filename alone can be revealing
  • Bank statements and tax returns sent to an accountant or mortgage broker
  • Passport and ID scans, which are routinely emailed in the clear during onboarding
  • Internal reports archived somewhere with broad access

PDFs often compress well, so enabling compression before encryption frequently produces a smaller file than the original.

[HOW TO ENCRYPT A PDF ONLINE]

Encrypt a PDF in your browser without uploading it to a server.

  1. Select the PDF. Choose your PDF with the file picker or drag it onto the drop zone. There is no size limit and nothing is uploaded.
  2. Enable compression. PDFs usually compress well, so the encrypted file is often smaller than the original.
  3. Choose a password or random key. Use a long passphrase, or generate a random 256-bit key for maximum strength.
  4. Download the encrypted file. You receive a .enc file that reveals nothing about the document, including its name and type.
  5. Share the key separately. Send the encrypted PDF and its key through different channels so intercepting one is not enough.

[FREQUENTLY ASKED QUESTIONS]

How do I encrypt a PDF online for free?

Select your PDF with the tool on this page, choose a password or generate a random key, and download the encrypted file. It runs entirely in your browser, so the PDF is never uploaded — there is no signup, no size limit and no watermark.

Is it safe to encrypt a PDF on a website?

Only if the encryption happens in your browser. Services that upload the document process it on their servers, which means your contract or medical record sits on a machine you do not control. This tool uses the Web Crypto API locally, and you can confirm nothing is transmitted in your browser Network tab.

Can this remove a password from a protected PDF?

No. A password set inside the PDF format is handled by PDF software — open it in Acrobat or another editor with the password and save a copy without it. This tool encrypts and decrypts the file as a whole rather than editing PDF internals.

What is the difference between a PDF password and file encryption?

A PDF password lives inside the document, so the file still looks like a PDF and its name is visible, and any reader can prompt for it. File encryption turns the whole document into an opaque .enc file revealing nothing about its type, name or size. The first is more convenient; the second protects more.

Can recipients still print or copy text if I restrict it?

Often yes. PDF "owner password" restrictions on printing and copying are advisory — the document is not actually encrypted, and many tools ignore the flags. Only a password required to open the file provides real encryption.