home » Articles » PDF »How to Unlock A PDF File When Forgot PDF Password

How to Unlock A PDF File When Forgot PDF Password

Encrypting a PDF file can enhance the security, especially for the PDF file that is quite important for you, you want to keep others from reading the file. However if you didn't touch the PDF file for a long time, you may forgot the PDF password. If you failed to unlock the PDF file after you had tried every possible password in your brain. Don't panic! Cocosenor PDF password tuner can help you. In this article, you will learn how to use this software to unlock a PDF file when forgot PDF password.

Step 1. Securely download the software from below link, and install it in your computer.

securely download Cocosenor PDF password Tuner for free

Step 2. Double click the icon to run the software, click Open to select the locked PDF file. For instance, now I have a locked PDF file, which was stored in the F disk in my computer. But you can select the encrypted PDF file in your computer.

import an encrypted PDF document

Step 3. Under "Type of attack", there are four types of attack -- Brute-force, Mask, Dictionary and Smart. As for the details of these four types of attack, please refer to four password attack methods to open encrypted file.

select type of attack

Step 4. For instance, I remember the password starts from "abc", no caps latin, special characters, space, and printable included, what's more, I know the password length is 7, then I can select Mask attack, and make further setting as below:

set for brute-force range options

You can choose an appropriate attack method according to your memory about password.

Step 5. After choosing attack type and making setting, click "Start" button, the software will automatically find the password. Once you get the password, you can use it to unlock the PDF file.


1. If your password is not longer than 3 characters, the free trial version is enough for you to recover the password. But if the password is longer than 3 characters, you need to buy a registration code.

2. During password recovery, you can pause and resume the project any time.

3. The password recovery time is related to the complexity of the password, if it's simple, you can get it very soon. But if it's rather complicated, you have to wait a bit longer time.

Related Articles