BROWSER-BASED PDF SECURITY TOOL

Protect PDF

Q: Are my PDF and password uploaded?

The protection process runs in your browser. The tool processing code does not send the selected PDF bytes or password to a conversion server. Website advertising and analytics are separate services.

Q: Can this protect a PDF that already has a password?

This version expects an unencrypted source PDF. Unlock an authorised copy first with the correct password, then protect it with the new password.

Q: Can the password be recovered if I forget it?

No. The tool does not store a recovery copy of your password.

Q: What happens to digital signatures?

Re-saving a signed PDF can invalidate cryptographic signature verification, so keep the original signed file when signature validity matters.

Add a password.
Keep your PDF private.

Encrypt a PDF with an opening password and download a protected copy. Processing happens in your browser.

AES-256 · Local processing · No conversion server

1Choose PDF
2Protect
3Download

Drop your PDF file here

or choose a document from your device

One PDF · Up to 25 MB · Password is case-sensitive

AES-256 password protection Processed in your browser Separate protected copy

From open PDF to password-protected copy

Your document stays a PDF. The tool adds standard PDF encryption rather than turning pages into images.

What happens

Your original PDF

Select an unencrypted PDF that you are allowed to protect.

A protected PDF

A new AES-256 encrypted copy is created and requires your password to open.

The source file on your device is not overwritten.

How to password protect a PDF online

Choose your PDF
Select one PDF up to 25 MB. The tool checks the file before processing.
Create a password
Enter and confirm a strong opening password, then confirm you have permission.
Download and test
Save the protected copy and open it once to verify that the password works.

What PDF password protection does

Password protection encrypts the document so a PDF reader needs the correct opening password before it can display the contents. This tool uses AES-256 encryption in your browser and creates a new protected file.

Password required to open

Recipients must enter the password before a compatible PDF reader can show the protected document.

Content stays in PDF form

Unlike image-based rebuilding, this process does not intentionally rasterize every page into JPEG images.

Creates a separate copy

The original file remains unchanged on your device. Downloaded output is a new protected document.

Not a DRM guarantee

Once an authorised recipient opens a PDF, a password cannot stop screenshots, photography or redistribution.

Re-saving a digitally signed PDF can invalidate signature verification. Keep the original signed document when signature validity matters.

How your PDF and password are handled

The selected PDF is read into browser memory and encrypted locally. This tool’s processing code does not send the PDF bytes or password to a conversion server.

Local processing

The encryption library loads from an external CDN. Your selected PDF and password are used in the current browser tab. The password fields are cleared after a successful run or reset, and generated download URLs are released when no longer needed.

Website services are separate

Advertising, analytics, consent tools and other website features can have their own data practices. Review your site’s privacy policy and configure those services appropriately before publishing this page.

Site privacy policy Report a problem Unlock PDF

Questions about protecting a PDF

How do I password protect a PDF online?

Choose an unencrypted PDF, create and confirm a strong password, confirm you have permission to protect the document, then click Protect PDF. Download the new protected copy and test it in a PDF reader.

Are my PDF and password uploaded?

The protection process runs in your browser. This tool’s processing code does not send the selected PDF bytes or password to a conversion server. The encryption library itself loads from an external CDN, while advertising and analytics on the surrounding website can have separate data practices.

What encryption does this tool use?

The tool requests AES-256 PDF encryption from its browser-side PDF library. AES-256 is used for the new password-protected output generated by this tool.

Can this protect a PDF that already has a password?

This version expects an unencrypted source PDF. If the source is already protected, unlock it first with the correct password and then protect the authorised copy with the new password.

Can the password be recovered if I forget it?

No. This tool does not store a recovery copy of your password. Keep the password in a secure password manager or another safe place before relying on the protected file.

Will text, links and images remain in the PDF?

The tool encrypts and re-saves the PDF rather than intentionally turning every page into an image. However, any rewrite can affect advanced PDF features, so review the downloaded file before sharing it.

What happens to digital signatures?

Re-saving a signed PDF can invalidate its cryptographic signature verification. Keep the original signed file when signature validity is important.

Does a password prevent someone from sharing the PDF after opening it?

No. An opening password controls access to the encrypted document. After an authorised person opens it, password protection cannot prevent screenshots, photographs or every possible form of redistribution.