PDF Tool Plus
Language: English
Prepare documents

Combine, split, arrange

Merge PDFSplit PDFOrganize PDF pagesAdd page numbers

Convert images and PDF

Images to PDFPDF to imagesConvert & resize imagesWord, Excel, PowerPoint to PDF

Reduce file size

Compress PDF

Fill, sign & stamp

Fill & sign PDFCreate fillable PDFWatermark PDF

Security

Redact PDFProtect PDFUnlock PDF

Recognize text, compare

Recognize text (OCR)Extract images & text from PDFCompare PDF
Guides

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Protect PDF

Lock a PDF with a password before emailing it or storing it on a shared computer — recipients need the exact password to open it.

Processed on your device — files are not uploaded to a server.

Add files to start

Drag and drop files here, or

Supported: PDF · Up to 20 files, 50 MB in total, 100 pages per session

Files are processed right on your device.

Password

People who open it with this password may

Permission restrictions are only enforced by PDF readers that follow the standard — they do not replace the password to open the file.

Keep the password somewhere safe: if it is forgotten, nobody can open the file — not even PDF Tool Plus.

Add a PDF without a password to protect it.

  • AES-256 encryption right on your device — the file and password are never uploaded or stored.

How to use

  1. Add the PDF files to protect (several files can share one password).
  2. Enter the password to open the file twice. Use at least 8 characters with letters and numbers.
  3. Optional: untick printing, copying or editing; set an owner password if you may want to change permissions later.
  4. Click “Protect PDF”, download the file and send the password through a different channel (for example a text message, not in the same email as the file).

Current limits

  • Uses AES-256, supported by current PDF readers; very old software (from before about 2010) may not open it.
  • A forgotten password cannot be recovered — PDF Tool Plus never stores it.
  • Print/copy/edit restrictions are only enforced by readers that follow the standard; for real secrecy, rely on the password to open the file.
  • Digitally signed files: the signature is no longer valid after adding a password. Files that already have a password: unlock them first, then set a new one.

Frequently asked questions

Is my password sent to a server?

No. Encryption runs in the browser on your device; the file and password are not sent anywhere and are not stored.

How should I share the password?

Use a different channel from the file — for example, email the file and text the password, or tell it by phone. Writing the password in the same email as the file makes the protection nearly useless.

What is the difference between the open password and the owner password?

The open password is what recipients need to view the content. The owner password is only for changing permissions such as printing, copying or editing; if you do not restrict anything, you do not need one.

Can I protect several files at once?

Yes, up to 10 files per batch with the same password. For a different password per file, run separate batches.

Does a password make the file larger or blurrier?

No. Page content stays as it is — nothing is turned into images — and the file size barely changes.