QRix
Remove password protection from a PDF you can already open.
This tool removes the password from an encrypted PDF, producing a normal file that opens without any password. You must know the current password to unlock it — this is not a password-cracking tool. Everything runs in your browser, so your file and password stay private. Only use this on documents you own or are authorized to unlock.
It's free, private and works right in your browser — no signup, no watermark.