PDF Password Protector
Files never leave your device
Drop a PDF file here
or click to browse. Password protection runs locally with qpdf-wasm.
What this tool does
  • Adds an open password, so the PDF asks for a password before viewing.
  • Uses qpdf-wasm in your browser to create 128-bit or 256-bit encrypted PDF output.
  • Lets you allow or block printing, copying, and editing permissions.
  • Creates a new protected PDF and never modifies the original file.
  • Runs locally. Your PDF and password are not uploaded to a server.
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PDF Password Protector - Encrypt PDF with Password

Add a password to a PDF locally in your browser using qpdf-wasm. No upload, no account, no watermark.

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About this tool

This free PDF Password Protector lets you password protect a PDF, encrypt a PDF with a password, and add an open password to a PDF online without uploading it. Upload a PDF, enter the password that should be required to open the document, confirm it, choose the encryption level, set whether printing, copying, and editing should be allowed or blocked, and download a new encrypted PDF. The work happens in your browser with qpdf-wasm, which is the qpdf PDF engine compiled to WebAssembly.

The tool is designed for private documents where uploading to a random online converter is not acceptable: client contracts, internal reports, invoices, proposals, HR packets, finance exports, legal drafts, and other files that should stay on your own device. Your PDF is read from disk into browser memory, written to qpdf-wasm's in-memory filesystem, encrypted locally, and downloaded back to you. The file and password are not sent to this website's server.

PDF password protection is useful when you need basic access control before sharing a document through email, chat, a shared drive, or a client portal. The protected output asks for a password before the PDF can be opened in normal PDF viewers. The permission controls let you allow or block printing, copying/text extraction, and editing/document modification. These permissions are respected by most normal PDF viewers, but they are not a substitute for strong access control once someone knows the password. This is different from PDF Watermark, which adds visible marks to the pages, and different from PDF Compressor, which reduces file size. If you need to remove a password from a document you own, use PDF Unlock instead.

For best results, use a strong unique password. Short words, project names, client names, birthdays, or reused account passwords are weak choices. A long random password or several random words is much safer. You can generate a strong value with Password Generator, protect the PDF here, and then send the password through a separate channel from the file itself.

Features

  • Password protect PDF files with an open password required before viewing.
  • Encrypt PDF output locally in the browser using qpdf-wasm, not a server upload.
  • Choose 256-bit PDF encryption for modern viewers or 128-bit encryption for older compatibility.
  • Confirm the password before processing to avoid downloading a file with a typo.
  • Optional owner password field for users who need separate owner credentials.
  • Allow or block printing permission in the protected PDF.
  • Allow or block copying and text extraction permission in the protected PDF.
  • Allow or block editing and document modification permission in the protected PDF.
  • Create a new protected PDF while leaving the original file untouched.
  • Download the encrypted PDF immediately as a new password-protected file.
  • Protect sensitive documents without account creation, email signup, or branding watermark.
  • Use alongside PDF Unlock, PDF Watermark, PDF Merger, and PDF Compressor workflows.
  • Clear local error messages for missing files, short passwords, and mismatched confirmation.

How to Use

  1. 1
    Upload the PDF you want to protectDrop a PDF into the upload area or click to browse. The browser reads the file locally and stores it in memory for qpdf-wasm. The original PDF on your device is not modified.
  2. 2
    Enter the open passwordType the password that should be required when someone opens the protected PDF. Use a strong unique password. If you need one, generate it with Password Generator and save it safely before encrypting the document.
  3. 3
    Confirm the password and optional owner passwordRe-enter the same password in the confirmation field. The optional owner password can be left blank; in that case the tool uses the open password as the owner password too.
  4. 4
    Choose encryption and permissionsUse 256-bit encryption for modern PDF viewers or 128-bit for older compatibility. Then decide whether the protected PDF should allow printing, copying/text extraction, and editing/document modification.
  5. 5
    Protect and download the encrypted PDFClick Protect & Download. The tool loads qpdf-wasm, runs qpdf encryption with your selected permissions in the browser, and downloads a new protected PDF. To remove protection later from a file you own, use PDF Unlock.

Common Use Cases

Password protect confidential PDFs before sharing
Add a password before sending contracts, legal drafts, statements, HR files, or internal reports by email. Use 256-bit encryption and block copying or editing when the recipient only needs to view the file. Send the password separately from the PDF so accidental forwarding does not expose the document immediately.
Encrypt client proposals and invoices as PDF files
Freelancers and agencies often send proposals, invoices, and payment documents that include private rates, addresses, or account notes. Protect the exported PDF before sending it to a client contact or accounting inbox, and decide whether printing should remain available for accounting workflows.
Protect forms and application packets
Application packets, insurance forms, school documents, onboarding paperwork, and identity documents may contain sensitive details. Add an open password so the PDF cannot be viewed casually if it lands in the wrong folder.
Use password protection after PDF editing workflows
First combine pages with PDF Merger, reorder pages with PDF Page Organizer, or add a visible mark with PDF Watermark. Then password protect the final PDF copy before distribution.
Create a protected PDF archive copy
When storing sensitive PDF records on a shared device or drive, create a protected copy for archive storage. Keep the original only where it belongs and store the password in a trusted password manager.
Combine PDF encryption with visible watermarks
A password controls opening the file, while a watermark labels the content after it is opened. For sample documents, review drafts, or restricted previews, add a watermark first and then protect the final PDF with a password.

Frequently Asked Questions

Open the PDF Password Protector, upload your PDF, enter and confirm the open password, choose the encryption level and permissions, then click Protect & Download. The tool loads qpdf-wasm in your browser, writes the PDF into an in-memory file system, encrypts it locally, and downloads a new password-protected copy. The PDF and password are not uploaded to a server.

It encrypts the PDF using qpdf-wasm, which is the qpdf command-line tool compiled to WebAssembly. The output PDF requires the open password before a normal PDF viewer can display the document. You can choose 256-bit encryption for modern PDF viewers or 128-bit encryption for older compatibility. This is different from simply adding a watermark, changing metadata, or putting the file in a ZIP archive.

Yes. The permission controls let you allow or block printing, allow or block copying/text extraction, and allow or block editing/document modification. These settings are written into the encrypted PDF by qpdf. Most PDF viewers respect these permissions, but they should be treated as viewer permissions rather than absolute prevention against every possible tool.

Use a unique password that is not reused on other accounts or documents. Longer passwords are better: a phrase of several random words or a 14-20 character random password is much stronger than a short memorable word. You can create one with the Password Generator and store it in a password manager before sending the protected PDF.

PDF encryption supports a user or open password and an owner password. The open password is what someone enters to view the PDF. The owner password is a separate administrative password used by PDF software for permission management. If you leave the owner password blank, the tool uses the same value as the open password.

Yes, if you know the password. Use the PDF Unlock tool, upload the protected PDF, enter the correct password, and download an unlocked copy. This tool is for adding protection; PDF Unlock is for removing protection from PDFs you own or have permission to access.

No. A PDF open password controls whether the file can be opened by a PDF viewer. After someone has the password and can view the document, they may still be able to screenshot, photograph, or manually copy visible information. For review copies or sample files, combine password protection with a visible watermark using PDF Watermark.

No. The original PDF remains unchanged on your device. The tool creates a new encrypted PDF in browser memory and downloads it with a new filename ending in password-protected.pdf. You can keep both copies or delete either one afterward.

The qpdf-wasm package runs the qpdf command-line engine inside the browser through WebAssembly. This build uses WebAssembly threads, which require SharedArrayBuffer support in the browser context. If the browser or hosting environment blocks those features, the tool will show an error instead of uploading the file elsewhere.