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Summary

Now, PDF is one of the common file formats. It is usually used to save the important contents which cannot be modified. You can use some tools to unlock the file when you forgot the password of the locked PDF file. In this essay, we will talk about how to unlock PDF and how to protect the locked PDF well.



Part 1: How to Unlock PDF?
There are many advantages of PDF. Compared with TIFF and JPEG, PDF can be protected well with the password. Therefore, if you care about the intellectual properties and the data security of the PDF files, you shall save the files as PDF and add password to protect them. The password-locked PDF files can be disabled to copy, edit, view and even print.
Two types of the locked PDF file:

● The file that can be merely viewed via the correct password, or be decrypted by the professional password cracker.

● The file that can be read only, but not to be copied, printed or modified without the correct password.

Sometimes, we download the locked PDF files online but we cannot open the files without the password. Next, we will talk about how to crack the password-protected PDF files with 3 ways.

Method 1: Unlock PDF with Renee PDF Aide

Renee PDF Aide is the software that supports to edit PDF and convert PDF. With utilization of the advanced OCR (Optical Character Recognition) technology, it can convert PDF to Word/Excel/PowerPoint/Image/HTML/TXT and the other common formats. Besides, it can repair the damaged PDF files, compress PDF files to shorten the loading time, merge several files into one and rotate the file position. En/decryption and watermark are allowed to add for PDF files, too.
Renee PDF Aide - Powerful PDF Editing Tool

Easy to use Friendly to computer beginners

Multifunctional Encrypt/decrypt/split/merge/add watermark

Safe Protect PDF with AES256 algorithms

Quick Edit/convert dozens of PDF files in batch

Compatible Convert PDF to Excel/PowerPoint/Text, etc.

Easy Use with simple steps

Functional Encrypt/decrypt/split/merge/watermark

Safe Protect PDF with AES256 algorithms

Free TrialFree TrialNow 800 people have obtained the free version!
Steps:
① Download and install Renee PDF Aide. Open the software and get into [PDF Tools].
select pdf tools in renee pdf converter
② Click on [Add Files] to select one or more files.

add files to encrypt in renee pdf aide
③ Select [En/Decrypt] at the top menu. Then, select [Decrypt PDF files]. Next, click on [Edit] to enter the possible characters of the password. Finally, click on [Convert] to decrypt the file.
encrypt pdf with renee pdf aide
remove signature and other restrictions from pdf with renee pdf aide
As the PDF file is unlocked, you can edit, modify and print the file. Within Renee PDF Aide, you can use the functions to split, merge, rotate and add watermark to the PDF files. Here are more details.
● Split PDF pages
If there are too pages, you can split the pages with Renee PDF Aide.
Steps:
① Open Renee PDF Aide. Then, select [PDF Tools] – [Add Files], and select the target PDF file.
② Select [Split] at the top menu. Select [Split into smaller files] or [Keep specified pages].
how to combine files into one pdf with renee pdf aide
③ Finally, click on [Convert] to split the pages.
● Merge PDF files
Renee PDF Aide can merge several PDF files into one easily.
Steps:
① Open Renee PDF Aide. Then, select [PDF Tools] – [Add Files], and select the target PDF files.
② Select [Merge] at the top menu. Next, select to merge all pages or some of the pages. After that, click on [Convert] to output the file.
merge pdf files with renee pdf aide
● Rotate PDF
To view the PDF file better, you can rotate the PDF pages.
Steps:
① Open Renee PDF Aide. Select [PDF Tools] – [Add Files], and then select the target PDF files.
② Select [Rotate] at the top menu. Next, select a rotation angle, 90, 180 or 270 degrees. Besides, select to rotate all pages or the specified pages.
rotate pdf page with PDF Aide
③ Finally, click on [Convert] to output the PDF file.
● Add watermark
Sometimes, we need to add the watermark on the PDF files in case that the PDF files are copied or stolen by the other people.
Steps:
① Open Renee PDF Aide. Select [PDF Tools] – [Add Files], and then select the target PDF file.
② Select [Watermark] at the top menu. Then, select [Add watermark] or [Add background].
select to add watermark or background in renee pdf aide
③ Click at the [] button at the end of [Watermark file] to select the target watermark.
④ Select to apply the watermark to all pages or some of the pages. Finally, click on [Convert] to output the file.

Method 2: Remove PDF Password with Google Chrome

If you know the password of the PDF file, you can remove the PDF file in Google Chrome. But if you don’t know the password, please try the method 1. The PDF reader is built in Google Chrome, which supports users to view the PDF files. As the PDF file is opened on Chrome, you can save the PDF file as the file without password. That is a way to remove password from a PDF file.
Note: Google Chrome cannot crack the locked PDF file. Please use the method 1 to decrypt the file if necessary.
Steps:
① Open the target PDF file with Google Chrome.
② Then, enter the correct password to open the PDF file.
③ Windows users press [Ctrl + P] and Mac users press [Command + P] to turn on the printing menu. The fact that you cannot turn on this menu means the PDF file cannot be unlocked.
⑥ Select [Save as PDF] and click on [Save].
Through the above steps, the PDF file will be saved as the file without password. You can double click to open the file.

Method 3: Unlock PDF Online

In addition to the two methods, you can unlock PDF online. You don’t need to download or install any application and unlock your files via the online tools. But these tools have some disadvantages. First, most of the online tools limit the file size that is being uploaded, up to 100MB. Besides, the network environment greatly affect the online processing time.
These are the online websites which can unlock the password-protected PDF:

1. http://freemypdf.com/

2. https://www.pdfunlock.com/

3. https://foxyutils.com/unlockpdf/

Here are the steps to crack PDF online:
① First, get access to one of the above websites.
② Upload the target file to the website.
③ Then, click on [Unlock] to unlock the PDF file.
Comparison between these 3 methods:
Renee PDF AideGoogle ChromeOnline tool
Conversion wayDownload&installDownload&installOperate online
File size limitationNo limitationNo limitationUp to 150MB
Cracking conditionCrack directlyKnow the passwordCrack directly
Easy to operateYesYesYes
Edit PDF××
We encrypt PDF because of data security. But the improving and updating decryption technology make the files to be easily unlocked. If you don’t want your PDF file to be cracked easily, how shall we encrypt the PDF files?
Part 2: How to Lock PDF?
PDF is widely used in many important files due to the convenient cross platform transfer, well visual experience and high security. We can encrypt PDF files, restrict file access and protect the file information. Some documents, such as contracts and dissertations, shall be saved as PDF. Next, we will introduce two encryption ways.

Method 1: Lock PDF with Renee PDF Aide

Renee PDF Aide can help you quickly encrypt PDF files with password. Users can also print, modify, fill in sheet and add digital signature. With the application of the AES356 encryption algorithms, it ensures the high data security and protects files from being stolen.
Windows 10/8.1/8/7/Vista/XP/2000 (32-bit and 64-bit) are available.
Renee PDF Aide - Powerful PDF Editing Tool

Easy to use Friendly to computer beginners

Multifunctional Encrypt/decrypt/split/merge/add watermark

Safe Protect PDF with AES256 algorithms

Quick Edit/convert dozens of PDF files in batch

Compatible Convert PDF to Excel/PowerPoint/Text, etc.

Easy Use with simple steps

Functional Encrypt/decrypt/split/merge/watermark

Safe Protect PDF with AES256 algorithms

Free TrialFree TrialNow 800 people have obtained the free version!
Steps:
① Download and install Renee PDF Aide. Then, open the software and get into [PDF Tools].
select pdf tools in renee pdf converter
② Click on [Add Files] to select the PDF file.
add files to encrypt in renee pdf aide
③ Select [En/Decrypt] at the top menu. Next, set a password and finally click on [Convert] to add the password to the PDF file.
encrypt pdf to lock with renee pdf aide

Method 2: Lock PDF Online

PDF Candy offers online conversion services. You can go through the simple steps to lock the PDF files for free. Its advantages are that you don’t need to install any software or register any account. But the disadvantages are that it is not safer than the encryption software, like Renee PDF Aide. Besides, it is affected by the network environment. We still recommend that you use the above method to encrypt the large file.
Steps:
① Get access to the website and click on [Add file]. Upload the target PDF file. Or, select the file from Google Drive.
② Enter the password and reenter to confirm the numbers. After that, click on [Protect PDF].
③ Finally, click on [Download file] to save the encrypted PDF file.
These steps are about how to add password onto the file. If you don’t like such method, you can try the following way to lock the PDF file. Besides, Word/Text/Excel can be locked in this way.
Part 3: Lock PDF with Renee File Protector
When you want to encrypt and transfer the important files, we suggest that you should use Renee File Protector. With the application of the AES256 algorithms, it can greatly protect the PDF files and protect them from being cracked easily.
Renee File Protector is the professional encryption software. It can encrypt, lock and hide files, folders and disks. That can restrict the other people to modify and view files. Besides, it can monitor files to protect your privacy.
press to the download button
Steps:
① Download and install Renee File Protector. Open the software. Then, click on [Lock File] under [Hard Disk].
lock file in Renee File Protector
② Then, click on [Lock File] to select the target PDF file. After that, the file will be locked.
Also, right click at the PDF file and select [Renee File Protector] – [Lock (Deny read + write + run)]. Then, enter the password to lock the file.
click to lock file in renee file protector
④ Next time, you should enter the correct password to unlock the file by right clicking at the file.
Right click at the target file and select [Renee File Protector] – [Enable (Allow read + write + run)]. Then, enter the password to unlock the file.
enter password to unlock a file with file protector
Part 4: Lock PDF with Renee SecureSilo
Renee SecureSilo is one of the hot encryption applications due to the high security and convenience. It offers various encryption ways, especially for a number of files. Many file types, such as PDF, Word, Excel and images, are supported to encrypt. Users can create a private silo and then put the important file into the silo. All files can be locked well and protected.
In addition, Renee File Protector can hide/disguise files and encrypt password wallet through the simple steps. Moreover, the format of the silo is private with the application of AES256, which is hardly decrypted by the common crackers.
press to the download button
Steps:
① Download and install Renee SecureSilo. Open the software and then set a login password.
set a new password for the virtual disk in renee secure silo
② Select [Encrypt File] – [Create Silo].
create a virtual disk in renee secure silo
③ Set the silo name and the storage position. Then, click on [Next] to continue.
name for the disk and set the storage position in renee secure silo
④ Set a password for the silo.
set a new password for the virtual disk in renee secure silo
⑤ After that, set a file size and click on [Next] to create the silo.
select a size range for the virtual disk in renee secure silo
⑥ In [Encrypt File], click on [Open Silo] to open the silo and put the PDF files into it to lock.
open the locked files in renee secure silo
save pdf files with renee securesilo