Lock PDF File – How to Password Protect PDFs

A distinct advantage of using PDF is the ability to safeguard its content with a password. PDFs provide ways to protect your sensitive information by locking PDF with password. This protection ensures that one will need to input that password whenever the PDF file is opened. Another way is to change the security settings of the PDF file to lock access to specific actions instead of password protecting PDF completely. But this has more to do with restricting permissions than protecting PDF.

Here, we will guide you through this process using the most popular PDF application i.e, Adobe Acrobat and its alternative. You can also use online solutions to lock PDF at your own risk. More on it later.

Protect PDF with Adobe Acrobat (Official)

Adobe developed PDF way back in 1992 to work with documents that preserve formatting independent of hardware, software and operating systems. It’s safe to say that they succeeded. Adobe also developed official solutions to work with PDF documents:

• Adobe Acrobat Reader DC: This is the standard edition of Adobe Acrobat free of charge. You can open, preview, and print PDF files and use tools to highlight parts of the text. However, you cannot work with PDFs and alter PDF files if you are a user of the free version.
• Adobe Acrobat Standard: It is a paid version with fewer options in comparison to the Pro version.
• Adobe Acrobat Pro: This version is a paid one and it has all the PDF tools which include creating, editing, converting, etc. It is usually available as a monthly or annual offering through Adobe’s website.

Use Adobe Acrobat Standard to Lock PDF with Password

You can apply several PDF security features with Adobe Acrobat Standard version:

1. Password Protection

• Set a password to open the document
• Create a separate password while adding PDF restrictions

2. Permissions Control

• Prevent printing
• Disable copying text and graphics
• Restrict editing
• Limit form filling
• Control document changes

The step-by-step process to protect protect a PDF with a password is as follows:

1. Open Adobe Acrobat Standard and in the menu at the top of the screen, click “File.”
2. After that, select “Open” and choose the PDF file you want to secure.
3. Now, go to Menu and Protect Using Password.
   
4. After that, select Viewing choice.
5. Enter a password which will be required each time anyone wants to open this PDF file.
   
6. Optional: Before saving the changes, check the box near “Editing” in order to set a different password for editing the document.
7. Now, select the required encryption class (we recommend setting 128 or 256 bits).
8. Apply the settings after confirming the password.
9. Lastly, click OK and then type your new password again when asked to do so.
10. Make sure to save the PDF document. This PDF file is now encrypted with a password.

Use Adobe Acrobat Pro to Protect PDF File

When it comes to PDF security, Adobe Acrobat Pro is the most suited to offer the best security for PDF files. We recommend this software to those professionals who work with sensitive and/or classified documents. It provides:

1. Advanced Password Protection

• Set Passwords to open the document
• High-level techniques of encryption
• Different passwords for different levels of permission.

2. Detailed Permission Controls

• Printing
• Copying
• Editing
• Form filling
• Document modifications

3. Additional Security Features

• Digital signatures
• Document tracking
• Watermarking
• Advanced encryption options

The step-by-step process to lock PDF with password using Pro application is as follows:

1. Open Adobe Acrobat Pro and locate the PDF file which you wish to protect.
2. Once the PDF is open, click on Tools toolbar at the top of the page and click on Protect. If it’s not immediately visible, then use the search bar at the top of the Tools tab to search for “Protect.”
3. In the Protect toolbar that appears, click on Encrypt and then choose Encrypt with Password from the options that will drop down.
4. A dialog box will pop up prompting you to choose the type of password security:
   1. Open Password: Requires a password to open the document.
   2. Permissions Password: Prevents operations such as modifying content, copying, or even printing any document without a password.
   3. (For this guide, we’ll focus on the Open Password option.)
5. Make sure the check mark appears in the check box labeled “Require a password to open the document.”
6. In the first box type in the password that you would wish to use and then repeat the same in the second box provided for confirmation.
7. Adjust the compatibility settings based on your needs:
   1. Acrobat X and later: Advanced security, which, however, excludes the possibility of working with earlier versions of Adobe Acrobat.
   2. Acrobat 7.0 and later: It provides a wider compatibility range; however, it still implements slightly less sophisticated encryption.
   3. Optional: If you are setting a Permissions Password make sure that you add other constraints like Printing, Changes etc.
8. After that, type in your preferred password settings and click OK to confirm these changes, and if you are asked to do so, type in the password once again.
9. In Acrobat, you will get a message that will inform you that the PDF is now password protected.
10. Save the newly protected PDF document by clicking on File > Save As.
11. Adobe Acrobat Pro automatically encrypts and secures the PDF document upon saving.
12. You can test the password protection by reopening the PDF file in any PDF application.

Use Free Adobe Acrobat Reader to Encrypt PDF with Password

The free version of Adobe Acrobat does not allow to password-protect a PDF file or add encryption to it. It only allows you to:

1. View PDF file
2. Print PDF file
3. Add comments
4. Fill out forms.

If you want to add password protection to a PDF, you will need to purchase the paid version of Adobe Acrobat software or use the alternative software.

Lock PDFs with PDF Protector (Alternative)

PDF Lock is one of the best PDF protection software available for Windows users. It comes with all the password features of Adobe Acrobat with only a one-time payment system instead of the subscription plan of Adobe Acrobat. It has several advanced PDF security features, such as:

• Lock multiple PDF files at once.
• Apply document open password for PDFs.
• Apply document restriction password
• 4 different encryption levels
• Keep source PDF password for protected files.
• Protect printing in PDF
• Protect copying in PDF
• Lock editing in PDF
• Option to restrict access and any changes.

The software is available for demo purposes (free tool) to help you test the features. This free demo version will lock PDF files but apply a watermark to them.

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Here are the steps to password protect a PDF using the PDF Lock tool:

1. Run the full version of the software on your Windows system.

2. Click on ‘Add File’ button to add one or more PDF files into the software.

3. Once the file(s) have been added, you can set the destination path to save the locked PDF.

4. Check mark the “Apply Document Open Password” option to protect a PDF document with a password.

5. Enter a password in the given boxes.
6. Now, apply the encryption method to encrypt the PDF file. RC4x128 is the standard encryption that all PDF applications support.

7. Click on the ‘Lock‘ button to start the process of locking the PDF file(s).

8. Congratulations, the process is complete. You can see the locked PDF files in the destination folder.

9. When you try to open the locked PDF file, you will get a prompt to enter the password.

Online Tools to Lock PDF with Password Protection

An online tool is the best solution to secure a PDF file that has no sensitive or confidential information. If you only want to encrypt one or two PDF files with password then simply use an online application to get the job done quickly.

The reason why real professionals recommend not to use online tools is the privacy factor. To use an online tool, you must upload your PDF file to their website. This PDF file is stored in their database server and you have no way of knowing whether that PDF is being used elsewhere. Since the entire process is online and not within the confines of your system, data privacy and security become a major concern. So it is recommended to avoid using online solutions to lock PDF if your file has important information. If it’s just regular data, then go for it.

Here are detailed steps to protect a PDF with a password using online tools:

1. First of all, select the most reliable online PDF Protection software.
2. Open the chosen website and click either on the Upload button.
3. Select the PDF you want to protect and upload it on the website.
4. Enter the password in the password and confirm password fields.
5. Click on the Protect button.
6. Last of all, save the password protected PDF on your system.
7. Launch the PDF and make sure that the PDF file is demanding for password.

Comparison Table

Feature	Adobe Acrobat	PDF Lock	Online Tools
Pricing	$19.99/month (Adobe Acrobat Pro DC)	One-time purchase ($29 approx.)	Free or limited-use plans available
Offline Capability	Yes	Yes	No (requires internet access)
Ease of Use	User-friendly with most features	User-friendly with advanced features	Simple but dependent on web speed
Advanced Security Options	Strong encryption (256-bit AES)	Strong encryption (256-bit AES)	Basic encryption which is often weaker
File Size Limit	No limit	No limit	Usually restricted (e.g., 5–50 MB)
Platform Support	Windows, Mac	Windows only	Web-based (works on all platforms)
Additional Features	Editing, signing, converting PDFs	Focuses on PDF locking and restrictions	Minimal; often only password setting
Data Privacy	Local storage	Local storage	Risk of uploading sensitive files
Lock Multiple PDFs	No	Yes	No
Best For	Professionals who require multiple PDF tools	Users seeking affordable and secure PDF locking	Casual users with limited needs

Key Points:

• PDF Lock provides a more affordable offline solution for PDF protection that provides essential encryption options. It is suited for users who want a lifetime license without recurring costs.
• Adobe Acrobat is best suitable for individuals who need multifaceted PDF solutions, even though it comes with higher and continuous charges.
• Online tools are suitable for infrequent and non-critical work since they have privacy issues and restricted capabilities.

People Also Ask – Most Asked Queries

Q: Can I Password Protect Multiple PDFs in a Batch?

Ans: It depends on the method you wish to use. Adobe Acrobat Pro & Online tools do not provide any option to do this. But, you can make use of PDF Lock software to process multiple files at once. Here is how the process goes:

1. Download, install, and run the PDF Lock software on your PC.

2. Click on the Add Files button and select multiple PDF files that you want to lock.
3. You can also add a folder containing multiple PDF documents using the Add Folder button.

4. Once you have all the PDF documents added, go to the next window and apply whatever type of password you want to set to lock a PDF file from editing.
5. Finally, click the Lock button to encrypt all the PDF files successfully.