Removing a password from a PDF requires knowing the current password — that's the starting point for every legitimate removal method. If you have the password, removing it is a quick operation in any PDF tool. If you don't have the password, the options narrow significantly depending on how strongly the file was protected.
When You Know the Password
The simplest method on any platform: open the PDF (entering the password when prompted), print it to a PDF printer, and save the output. The resulting PDF has no password because printing creates a fresh file from the rendered output rather than copying the original's security settings. On Mac, use File → Print → Save as PDF. On Windows, use Microsoft Print to PDF. This works for both open passwords and permissions passwords.
For a cleaner result that preserves text quality better than the print approach, use a dedicated tool. WukongPDF's Unlock PDF tool accepts the file and password, strips the protection, and returns an unprotected version. Adobe Reader with the correct password open: File → Properties → Security → change to No Security and save. In Preview on Mac: open with the password, File → Export as PDF, and the exported file has no password.
Permissions Passwords vs. Open Passwords
There are two types of PDF password and they work differently. An open password prevents anyone from opening the file without it — you can't view the content at all without the password. A permissions password (also called an owner password) allows the file to open but restricts what you can do with it: printing, copying, editing may be blocked. A file can have either, both, or neither.
Permissions-only PDFs — those that open freely but restrict printing or copying — are the easier case. Since you can already open the file, the print-to-PDF method bypasses the restrictions without needing the owner password. The resulting file has neither restriction. This is appropriate when you have a legitimate right to use the content (it's your own document, or you received it and the restrictions are unnecessary for your use case).
If You've Forgotten the Password to Your Own Document
Losing the password to your own PDF is a frustrating situation. Recovery options depend on how strong the password was. PDFs protected with older 40-bit RC4 encryption (common in files created before 2008) are vulnerable to password recovery tools that can work through combinations quickly. Modern PDFs using AES-256 encryption with a long, random password are computationally infeasible to crack.
If the password was short or based on something predictable — a name, a date, a dictionary word — password recovery software like Passware Kit or PDF Password Genius can sometimes recover it through dictionary and pattern-based attacks. If the password was genuinely random and long, no practical recovery method exists. The only path forward is finding another copy of the document or reconstructing it from scratch.
Automating Password Removal for Multiple Files
If you have a batch of password-protected PDFs all using the same password — a common scenario when downloading documents from a system that applies the same protection to everything — processing them one by one through a browser tool is slow. Ghostscript handles batch password removal via command line: the -sPDFPassword= flag supplies the password, and a simple script can process an entire folder of files. For organizations regularly dealing with large volumes of protected PDFs, this is significantly more efficient than any manual tool.