Guaranteed PDF Decrypter 4.0

for Windows, Linux, Mac OS with GPU support

New 4.0 version with Unicode, 64-bit, Windows 10 support 50% discount

 PDF restrictions remover 

 PDF open password remover (40-bit) 

 PDF open password recovery (128 or 256-bit)


How to remove security from secured PDF file

PDF security overview

There are two types of secured PDF documents: your file can ask for password when opening the document, or, your file opens normally, but some operations are restricted (e.g, printing or editing) and requires password for unlocking it. The first password is known as document open (or user) password, and the second is permissions password (also known as a master or owner password). Adobe Acrobat uses different algorithms to apply PDF security with 40, 128 and 256 bit keys.

  • PDF restrictions are insecure and permissions password could be removed instantly.
  • If open password uses 40-bit keys (Acrobat 3 compatible encryption), it also could be removed with guarantee.
  • Searching for open password with 128 or 256-bit PDF encryption is only possible using PDF password recovery software.

Guaranteed PDF Decrypter purpose

The primary goal of GuaPDF is to
  • remove restrictions (unlock) of any secure PDF document (you should have the right to do it, for example, if you forgot the password). Any Acrobat version up to X is supported, even with 256-bit AES or 128-bit RC4 encryption. PDF restrictions removal is an instant process. Unlocked file can be opened in any PDF viewer without any restrictions so you may edit, copy or print it.

GuaPDF can be also used for
  • remove PDF user password (a.k.a. open password). Decryption of the file with password for opening is guaranteed for old PDF documents with 40-bit key only. This process takes 1-2 days on one modern desktop computer and could be accelerated on GPU.
Only standard PDF security is supported, neither third-party plug-ins nor e-books.

This is GUI utility for Windows and command-line (CLI) utility for Linux, Solaris/SunOS, Mac OS X.


Advantages of GuaPDF are:
  • Guarantee of removing restrictions regardless of password and encryption type used
  • Newest PDF 1.7 ExtensionLevel 8 (Acrobat X, XI, DC) files support, including AES encryption, Unicode passwords, compressed files and unencrypted metadata
  • Removal of some restrictions in signed or certified files by digital signatures and in PDF forms
  • Very high speed (40-bit key searching procedure is optimized for modern Intel Core and AMD architecture
  • GPU acceleration on modern NVIDIA and AMD cards using OpenCL technology
  • Versions for quad-core/multi-GPU processors and network distributed version to use power of distributed clients
  • Portability (Windows, Linux, Mac OS X versions are available)
  • Running in GUI and keeps running in batch mode (as command-line utility)

Unique GuaPDF features

  • GuaPDF is the first PDF password remover software ever!
  • Acrobat X encryption support
  • Unlike most PDF password crackers, your PDF file is not altered in any way (except the decryption), even the file size is often the same. That minimizes the possible incompatibility of the unlocked PDF file.
  • GuaPDF is the first and unique software with GPU acceleration of user password removal.
  • GuaPDF has special support of PDF forms.
Designed for NVidia CUDA Designed for OpenCL

GuaPDF Free version download  

This is FREE (DEMO) version that can process only small files! If you've got blank pages or any errors, please purchase full version.

Win64 NEW GuaPDF v. 4.0 Free Demo for Windows, GUI version, CPU client

GuaPDF v. 4.0 Free Demo for Windows, command-line version, CPU+GPU clients

Here is the installation instructions with screenshots.
If you got error message like "The application has failed to start because the application configuration is incorrect" you should install Microsoft Visual C++ 2017 Redistributable Package

Linux GuaPDF v. 3.3 Free Demo for Linux, CPU+OpenCL clients

Mac OS X GuaPDF v. 3.3 Free Demo for Mac OS X, command-line + applescript, CPU + OpenCL clients

Here is the installation instructions with screenshots.

Windows screenshot

Mac screenshot

Order GuaPDF full version

GuaPDF restrictions remover

Remove restrictions on PDF files (remove permissions passwords), and can't decrypt files with open password. Supports all version of Acrobat
License: personal, for one PC
GPU support: not needed

Purchase via ShareIT

Purchase via ShareIT

GuaPDF password remover

Support of both security methods (i.e. open and permissions passwords), and supports up to Quad-core CPU.
When removing open password, only old Acrobat files with 40-bit keys are supported
License: personal, for one PC
GPU support: one AMD/NVIDIA card. On modern GPU it takes only few hours to remove ANY open password with 40-bit key.

Purchase via ShareIT

GuaPDF unlimited

Support any number of CPU/GPU clients and distributed processing.
License: business, for any number of computers
GPU support: unlimited AMD/NVIDIA cards.

Purchase via ShareIT

GuaPDF upgrade

Upgrade from old version or from restriction remover to password remover here.
All 2019 customers may receive latest 4.0 version for free!. Just send a mail with your order ID to

Customer's FAQ

  • Q. I got the error message when starting the software: "The application has failed to start because the application configuration is incorrect" or "The code execution cannot proceed because *.dll was not found"

    A. Try to install Microsoft Visual C++ 2017 Redistributable Package

  • Q: How to use my GPU card?

    A: GPU acceleration is used only if your file has password to open with 40-bit key. Also, you need modern NVIDIA or AMD and the latest OpenCL drivers.

  • Q: What version should I choose?

    A: If can open PDF file, but can not print, edit etc, get the restriction remover version. If you can't even open file, first of all you need to test your file (using DEMO version) if it has 40-bit key encryption. If yes, you may choose any version depending of number of computers you've got.

  • Q: I've tested GuaPDF DEMO on my file, but got only blank pages (or some errors)

    A: DEMO version can process small files only. In fact, unlike other PDF decrypion software, GuaPDF don't change anything in your file structure, it only decrypts all encrypted streams and strings. That's why the decryption is guaranteed: your file is not modified (even the file size is often the same after decryption). DEMO version has only one possible limitation: it decrypts only few streams, all others streams remain encrypted. So, if the large files contains more streams than DEMO limitation, the decryption may cause any errors and blanks (non-decrypted) pages.

  • Q: Ok, but how can I sure the full version will work on my file?

    A: If DEMO version parses your file with no errors and the key is printed, the full version will work fine, because the decryption with known key is trivial.

  • Q: Ok, how long will it take?

    A: Restriction removal is instant (may be few minutes on very large files). To estimate key searching time, run DEMO version (and divide it to the number of your PCs/CPU cores).

  • Q: Are non-standard security handlers supported?

    A: No, please run DEMO to make sure your file is supported.

More questions and answers you'll find in the included documentation and here.


Only legal customers are supported. No claims and question about freeware version will be accepted, but I'll appreciate the constructive feedback. Also contact me if you have any problems with ordering the program.

Please send any comments and bugs to In case of the bug reported I'll update program as soon as possible.

You may submit your opinion / read others opinions here.

Refund policy

If your PDF is broken after decryption, the full refund will be immediately made.
  Last updated: 07 Jan 2020 © Pavel Semjanov, 2000-19