PDF Commons

Protect PDF

Locks the PDF with AES-256 and a password you choose. Encryption runs in this tab. The file is not uploaded.

A $6 day pass is 24 hours, charged once, and it does not renew. Pricing

No ad script loads from this choice. It stays in this browser.

What this protect changes

Protect PDF takes one PDF and the password typed into the field. The field is type=password, and autocomplete is off. The in-browser worker encrypts that PDF with AES-256. The same chosen string is both the user password and the owner password. The job is JSON, so a password that starts with a hyphen is not parsed as a flag. The download is one PDF named protected.pdf. It is not a zip. The original file on the computer is not rewritten. The result is still a PDF. It is not Word and not a picture. PDF Commons does not add its own watermark, logo, or trial line.

This runs in the browser tab, using the in-browser worker. The PDF is not uploaded. Open the network panel, drop the file, type the password, and the PDF should not appear as an upload. Encryption stays in the tab, and the browser offers protected.pdf as the download. Closing the tab drops the copy. The form does not send the file anywhere else, and it does not ask for an email.

There is no account and no page cap on this local tool. The tab has to hold the file. There is no published length cap on the password. A day pass is $6 and does not renew. A year is $60. Neither charge is required to protect here. The free server file is PDF to Word, one file, up to 20 pages, and that page uploads. Protect is not that offer. OCR and heavy compress are not free. Merge, split, and organize are separate local pages, and none of them is this encrypt step.

An empty password fails with "Choose a password." Failure of the encrypt job is "Could not protect this PDF." This page does not remove a password and does not guess one. A successful run still returns one PDF named protected.pdf, not a zip, not Word, and not a picture. If the tab cannot hold the file, the encrypt cannot finish here.

Steps

  1. Drop the file. It stays in this tab.
  2. Set the one option on the page, if it has one.
  3. Download the result. Closing the tab drops the copy.

Questions

Which password is written into the PDF?

The password typed into the field. The field is type=password with autocomplete off. An empty password fails with "Choose a password." There is no published length cap. The worker encrypts with AES-256. The same chosen string is both the user password and the owner password. The job is JSON, so a password that starts with a hyphen is not parsed as a flag.

Does protect upload the PDF?

No. This runs in the browser tab, using the in-browser worker. The PDF is not uploaded. Open the network panel, drop the file, type the password, and the PDF should not appear as an upload. Closing the tab drops the copy. The original file on the computer is not rewritten. The download is one PDF named protected.pdf. PDF to Word is the page that uploads, one file, up to 20 pages. Protect is not that offer.

Will this page open a PDF I cannot unlock?

No. This page does not remove a password and does not guess one. Unlock PDF is the separate page. Unlock asks for a password the visitor already knows, and a wrong password fails with "That password did not open this PDF." Unlock does not crack a password.

Do I need an account before I protect a file?

No. There is no account and no page cap on this local tool. A day pass is $6 and does not renew. A year is $60. Neither charge is required to protect here. The free server file is PDF to Word, one file, up to 20 pages, and that page uploads. OCR and heavy compress are not free.

Also