Password protect PDF

Encrypt a PDF with a user password so viewers must unlock it to open.

Runs on your deviceFreeNo account

How to use Password protect PDF

Open Password protect PDF. Encrypt a PDF with a user password so viewers must unlock it to open. Set the options, then copy or download. Files and text stay on your device. Built for phones and desktops.

Add your file

Drag & drop, browse files, or press Ctrl+V to paste from the clipboard where supported.

Process in the browser

Work stays in this tab with WebAssembly, Canvas, or other on-device APIs — your file is not uploaded to Omnipus.

Download or share

Save the result to your device, or share it with the OS share sheet when available.

Direct share: Install Omnipus as an app on Android to share files and links into this tool from other apps.

About this tool

Encrypt a PDF with a user password so viewers must unlock it to open. AES-256 encryption runs locally. Remember the password — Omnipus cannot recover it. Browser limits apply on huge or exotic files. Password protect PDF on Omnipus runs in this tab with no upload. No account, watermark, or daily cap.

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Frequently Asked Questions

Is Password protect PDF free?

Yes. No signup, watermark, or conversion quota.

Do you upload my PDF?

No. Encryption runs in this browser tab. The password never leaves your device.

How strong is the encryption?

Omnipus uses AES-256 via a pdf-lib build that writes a standard security dictionary. Use a long, unique password. This is not a substitute for full-disk encryption or enterprise DRM.

Will every PDF viewer open it?

Modern viewers that support AES-256 PDF encryption should. Very old readers may not. Large or unusual PDFs can fail in-browser — try a simpler export if that happens.

Can Omnipus recover my password?

No. If you forget it, only you (or a recovery process you control) can regain access.

Is Password protect PDF completely free to use?

Yes. Password protect PDF on Omnipus is free to use with no subscription paywall for the tool itself.

Are my files or data uploaded to any servers?

No. Password protect PDF processes your input locally in this browser tab. Your files and text are not sent to Omnipus. Some tools download an engine or model file the first time you use them; that is a download, not an upload.

Does Omnipus add watermarks to exported files?

No. Omnipus does not stamp a site watermark onto files you export from Password protect PDF.

Can I use Password protect PDF on my mobile phone?

Yes. Omnipus has touch-friendly controls and can be installed as an app. On Android you can also share files or links into tools from other apps.

Related tools

More pdf tools that pair well with this one.

Unlock PDFOpen a password-protected PDF when you already know the password, then download an unlocked copy.Compress PDFShrink PDFs with Raster (max shrink) or Light (keep selectable text) mode.Merge PDFJoin multiple PDFs into one document, in any order.PDF to WordExtract readable text from a PDF into an editable Word (.docx) file.Word to PDFConvert DOCX to PDF in your browser — layout may change on complex documents.JPG to PDFCombine one or many images into a single PDF.