Password-protect a PDF:the password never leaves your device

Drop the file on the upload card, type a password, and type it again to confirm. Four characters is the minimum the tool accepts, though a real passphrase is a much better idea.

Click Encrypt and the locked copy downloads with -protected added to the file name. Your original stays on your device, untouched and still openable without a password.

A file worth locking is usually a file you do not want sitting on someone else's disk. Most online protect tools take the upload, encrypt it there, and hold a copy for some hours before deleting it. They also see your password on the way through.

Here the encryption runs inside the browser tab. The bytes and the passphrase never travel, so there is no server copy to delete and no password in anyone else's logs.

The lock is the standard PDF password encryption built into the format, so Acrobat, Preview, Chrome and every other reader will prompt for it. The strength follows the PDF version of the file you upload, because that is what the format allows.

Files written as PDF 1.6 or 1.7, which covers most documents from modern software, get 128-bit AES. Files saved as PDF 1.4 or 1.5 get the 128-bit method those versions support, and anything older falls back to 40-bit. If a file matters a lot, re-save it from a current app first so it carries a recent version number.

PDFs have two passwords. The user password is the one that opens the document. The owner password unlocks full rights over it: printing, copying, editing. A file can have one, the other, or both.

This tool asks for one password and uses it for both roles. That means the person who can open the file also holds owner rights, so the permission boxes below are a polite request to the reader app rather than a hard lock. The real protection is that nobody gets in without the password.

Three checkboxes cover the common cases. Printing is allowed by default. Copy and paste and editing are both off by default, which is what most people want when they send a signed contract or a statement.

Adding comments and filling in form fields stay allowed either way, so a locked form is still usable by the person you sent it to.

Encryption controls who can open the file. It does nothing about what happens after that. Anyone who has the password can take a screenshot, print to PDF, retype the contents, or forward the file and the password together.

It also does not hide anything from someone who already has the unlocked copy. If specific words must never be readable, take them out of the document before you lock it.

Send the file and the password by two different routes. A password in the same email as the attachment protects nothing, since one leaked inbox gives up both. Message the passphrase, say it on a call, or agree it in advance.

These are the documents people most often need to lock, and the ones they should least want to hand to a stranger's server. The whole job here happens in the tab, so the statement never leaves your machine on the way to being encrypted.

Once a PDF is encrypted, most tools cannot read it any more, including ours. Merge, sign, number the pages, compress, and then protect the finished document. Otherwise every change means unlocking and locking again.

Signing and locking answer different questions: a signature says who agreed, a password says who may open. Place the signature first, save, then run the signed file through this tool.

The upload card will not read an encrypted file, so a file that is already locked has to be unlocked first. Remove the old password, then run it through here with the new one.

A password and a visible stamp do different jobs. The stamp tells a reader that the copy is confidential or a draft, the password keeps other people out. If you want both, add the stamp first and encrypt afterwards.

The tool is a web page, so there is no app to install. Pick the PDF from your files, cloud drive app, or a chat attachment, type the password, and the locked copy lands in your downloads folder.

Nobody can get the file back for you. No copy of your document or your passphrase exists here, so there is nothing to reset. Keep the original unlocked file somewhere safe, and treat the encrypted copy as the one you hand out.