Locked PDFs: open, unlock, re-protect — and why no tool here guesses passwords
What a PDF password protects, what you can do once you have it — unlock, edit, re-protect — and why no tool here guesses passwords.
UnboundPDF is a free suite of 54 PDF and image tools that run entirely in your browser — merge, split, compress, edit text, OCR in 126 languages, redact, sign, convert and archive to PDF/A. Your document is read and written by the page on your own device; there is no document-upload endpoint in the core tools, no account, no watermark and no daily cap. Every result can be checked — with the Network tab, or with the Document Passport the Workspace writes for a chain of steps.
Short answer. With the password, Unlock PDF removes it on your device and every other tool works on the copy; when you are done, Protect PDF encrypts the result again. Without the password, nothing here opens the file — by design.
Two kinds of password
A user password is needed to open the file at all. An owner password lets it open but blocks editing, printing or copying. Both are AES encryption; both are removed by Unlock PDF when you supply the password that applies.
Why the tools refuse locked files by name
Merge, compress, split and the rest cannot read an encrypted document. Rather than failing quietly, they name the locked file so you know which one to unlock.
Why there is no "forgot password" here
Cracking a password is guessing, and a strong one cannot be guessed in useful time. More to the point, a tool that tried would be a tool for opening other people's documents. If you lost your own password, the unprotected copy in your records is the answer.
Re-protecting
After editing or merging, Protect PDF encrypts the result with a new password — asked each run and never stored, including in Workspace recipes and passports. Share the password by a different route than the file.
Where it runs
Unlocking and protecting happen in your browser; a password and its file never travel together to anyone.
Frequently asked questions
Can you remove a password I do not know?
No. The tools unlock only with the password and do not attempt to guess one.
Is the password sent anywhere?
No. It is used in your browser tab and not stored.
Does unlocking reduce quality?
No. Decryption leaves the content unchanged.
Try it yourself
Free, private, no account. Runs entirely in your browser.