Quick clarification upfront: this is for removing passwords from PDFs where you already know the password. It doesn't guess or crack anything. If you've forgotten the password entirely, it won't help.
What it's for: you have a PDF, you know the password, and you're tired of entering it every time. Or you need to merge or split a locked PDF with another tool, and those tools require the file to be unlocked first.
How to do it
Go to pdfmerger.io/unlock. Upload your password-protected PDF. Enter the document password when prompted. Click "Unlock PDF." Download the unlocked version.
The result is a standard, unrestricted PDF. No password to open it. Printing, copying text, and editing are all permitted.
Your password never leaves your device
This is the part that actually matters. Most online PDF unlocking tools send your file to a server to be processed — which means both your document and the password you type are transmitted over the internet to a third-party server.
This tool processes everything locally in your browser. The password you type is used on your device to decrypt the file using the pdf-lib library. It's never transmitted anywhere. Neither is the PDF. This matters especially because protected PDFs usually contain sensitive content — that's typically why someone password-protected them in the first place.
What types of protection get removed?
Both types: the open password (required to view the file at all) and permission restrictions (restrictions on printing, copying, editing). After unlocking, the PDF behaves like a completely normal document.
What if the unlock fails?
If you're entering the correct password and the unlock fails, the PDF may use an unusual or non-standard encryption scheme. These are rare but they exist. In that case, the tool can't help — you'd need the original application that created the PDF.
After unlocking
You can use the unlocked file with any of the other tools — merge it with other documents, split it into sections, compress it, or convert it to another format. The workflow is: unlock first, then do whatever else you need.
Legitimate use only
This tool is for people who already have the password and want to remove the ongoing restriction. It's not for accessing documents you don't have permission to open.