Where to find the password
Look in the email, SMS or letter that came with the file. Companies often use something you already know, like a date of birth or part of a customer or employee ID, and usually say which in the message. If you can't find it, ask the sender.
Only unlock files you're allowed to open
This tool needs the password. It cannot guess, crack or bypass one, and it can't open a file whose password you don't have. It's meant for documents that are yours, or that you've been given the password to, such as your own statements, payslips or ID.
Removing a password doesn't change who owns a document. Don't remove restrictions from files you aren't permitted to copy or share.
Why it's safer than upload sites
Most online unlockers send your PDF, and often its password, to a server. A bank statement or ID card is exactly the kind of file you don't want sitting on someone else's machine.
Here, the file is read and processed inside this browser tab. The page's security policy blocks network requests to other sites, so the file and password have nowhere to go. After the first visit it also works offline.
Questions
Can this tool recover a forgotten password?
No. It only works when you already know the password. It does not guess or crack passwords, and a strongly encrypted PDF can't be opened without it.
The password is rejected. What should I check?
Check capital letters, spaces and the keyboard layout, and try the password with Show turned on to spot typos. Make sure it belongs to this particular file; different documents from the same sender can use different passwords.
What if the PDF opens without a password but I can't print or copy?
That PDF has restrictions rather than a password. Drop it in; after you confirm you have the right to, the tool saves a copy without the restrictions.
Does it work offline?
Yes. After the first visit the tool is cached by your browser and can run without a connection.