Opening a PDF and finding "can't copy text" or a grayed-out print button is a completely different mechanism from a file that requires a password before it opens at all — and the two provide very different levels of actual security.
Permission flags: more of a "please respect this" rule
The PDF spec lets a file's creator set a group of permission flags — "no printing," "no copying text," "no modifying content." Well-behaved readers and editors read and honor these, disabling the corresponding buttons accordingly. But this is fundamentally just "a request written into the file" — there's no real technical barrier stopping content from being accessed, and various tools or methods can bypass this layer.
Password encryption: a genuine technical barrier
PDF also supports two kinds of passwords:
- Open/user password: the file's content itself is encrypted — without the correct password, no software can decrypt and display it. This is genuine security.
- Permissions/owner password: locks the permission flags mentioned above so an ordinary user can't casually change those restrictions, while the file itself still opens and reads normally.
When each one is actually appropriate
- Just want to signal "please don't print or copy this": permission flags are enough — in most legitimate use cases, people respect that signal.
- Content is genuinely sensitive and must never be opened by an unauthorized person: requires open-password encryption — permission flags don't accomplish this at all.
What happens editing a restricted PDF
If a PDF has an open password set, no editing tool — LocalPDF included — can open or edit it without knowing that password; that's exactly what password encryption is designed to do. If only permission flags are set (the file opens normally), whether editing is possible depends on whether a specific tool chooses to honor those flags. When working with someone else's document, confirm you actually have permission to modify it rather than relying on whether it's technically possible to bypass the flag.
Working with a PDF that has no password protection? Just open it and start editing.
Open LocalPDF →