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Pro Guide on How to Combine Password-Protected PDF Files

  • By Steven
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  • Updated on October 23, 2025
Introduction:
It is not difficult to combine multiple PDF files into a single document. But what about merging password-protected PDFs? It can also be an easy task if you use the right PDF tool. In this SwifDoo PDF guide, I’ll walk you through a comprehensive guide on how to combine password-protected PDF files in several workable and reliable ways.
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Types of PDF Password Protection

Before merging, it helps to know what kind of password you’re dealing with:

  • User password (open password): Required to open the PDF. You must enter this to view the file.
  • Owner password (permissions password): Restricts actions like printing, copying, or editing, but may allow opening. Some tools respect these restrictions; others can remove them if you supply the password.

If a PDF only has an owner/permission password (restrictions on printing/copying/editing), there are technical ways to remove those restrictions and then combine files — but only if you have the right to do so. Bypassing passwords without permission may be illegal or against policy.

How to Combine Password-Protected PDF Files with SwifDoo PDF

SwifDoo PDF is a reliable PDF merger that supports combining PDF files into one file effectively. Does it support combining locked PDF documents? Of course! It enables you to bypass passwords, whether you know them or not. Hence, you can use it to merge password-protected PDFs. Here, you can check the steps below to perform the task using SwifDoo PDF.

Step 1. Click the button below to download and install this excellent PDF merger on your PC. Then, launch it to get to its main interface.

Step 2. Click the Merge PDF option under the default Home tab.

Click the Merge PDF option in SwifDoo PDF

Step 3. In the pop-up window, click the + Add Files option to import the password-protected PDF files you want to combine. Once uploaded, if your imported PDF files are protected by open passwords, a pop-up will appear, prompting you to enter the password. If you know the password, enter it and click OK. If you don’t know the open password, ask the PDF owner for help.

Enter the open password and click OK in SwifDoo PDF

Step 4. Then, you can rename the combined file and choose a folder to save it. Finally, click the Start button.

If your PDF files have permission passwords to protect them from merging, you need to remove the passwords first. In that case, follow the steps below to unlock PDFs in SwifDoo PDF.

Step 1. After running this PDF unlocker, import the locked PDF file.

Step 2. Click the Protect tab from the top menu bar and click the Decryption option.

Click the Decryption option under the Protect tab in SwifDoo PDF

Step 3. Tick the “No, I don’t have a permission password” option and click Next. Then click the Remove button to confirm the operation. Later, choose a folder to save the decrypted PDF file. Repeat the operation to remove permission passwords.

Tick the “No, I don’t have a permission password” option in SwifDoo PDF

Step 4. Next, switch from the Protect tab to the Page tab and click the Merge option.

Go to the Page tab and click the Merge option in SwifDoo PDF

Step 5. Click + Add Files to upload other PDF files you want to combine, and click the Start button to activate the PDF merging process.

How to Combine Password-Protected PDF Files with Adobe Acrobat

Adobe Acrobat is the leading PDF tool, equipped with a wide range of useful features. You can use it to encrypt PDFs with passwords as well as set PDFs to no security. To combine password-protected PDFs into one using Adobe Acrobat, you need to set the PDFs to no security first and then use its Combine PDFs feature to combine them. Now, let’s learn how to do that.

Step 1. Download and install Adobe Acrobat first. Launch it and log in to your Adobe Acrobat Pro account.

Step 2. Select the Open option from the File tab to import the PDF. Then, click File again and select Properties to open the Document Properties window.

Go to the Security tab and select the No Security option for Security Method in Adobe Acrobat

Step 3. Go to the Security tab, set the Security Method to No Security, and click OK to save the operation. Later, save the changed PDF file. Repeat the operation to remove the protection.

Step 4. Click the Tools tab and select the Combine Files option. Next, click the Add Files button to import the decrypted PDFs and click the Combine button to combine them.

Click Tools and select the Combine Files option in Adobe Acrobat

How to Combine Protected PDF Files Using Smallpdf

If you don’t want to download and install any software, consider online tools to merge PDFs. When it comes to online tools, most of us prioritize security as the primary criterion for selecting one. Among various online PDF tools, I strongly recommend Smallpdf.

Step 1. Go to the Smallpdf official website. If your PDF files have permission passwords, use Smallpdf to unlock them first. Open the Tools list and select the Unlock PDF option.

Select the Unlock PDF option from the Tools list in Smallpdf

Step 2. Then, click CHOOSE FILES to upload your PDF files. Next, click Unlock and download the decrypted PDFs.

Step 3. Go to the Merge PDF site of Smallpdf and click CHOOSE FILES to import the target PDFs.

Click CHOOSE FILES to import PDFs for merging in Smallpdf

Step 4. Click the Finish button in the top right corner to initiate the process. Once done, click the Download button to save the combined PDF file.

Wrapping Up

That’s all about how to combine password-protected PDF files. You can use Adobe Acrobat to complete the PDF combining task and perform other professional PDF tasks. If you need an affordable way, consider an Adobe Acrobat alternative, like SwifDoo PDF. Additionally, you can use online PDF tools. The above has shown detailed guidance. Now, it’s your time to have a try.

People Also Ask

  • Q: Can you combine password-protected PDF files?
    Yes, you can combine password-protected PDF files, but there’s an important condition: you must know and unlock each file’s password first before combining them.
  • Q: How to merge PDF files that are locked?
    To merge locked PDFs, you need to unlock them first and then use a PDF merger to combine them. To do that, you can try Adobe Acrobat Pro. Import the PDF file first, click File to choose Properties, and set Security Method to No Security. Next, select the Combine PDFs option from the Tools list to combine your PDF files.
  • Q: Can I edit a PDF that is password-protected?
    Of course, you can edit a password-protected PDF file. If you are the PDF file owner or the one who knows the passwords, you can easily edit it. If you don’t know the password, you need to use a professional PDF editor with the feature to unlock PDFs. SwifDoo PDF is an excellent PDF editor that can remove passwords from PDFs and offers a wide range of editing features for PDFs.

Steven is a dedicated contributor at Swifdoo.com. He possesses a deep understanding of various technology domains, including PDF software, program components, and video recording software technologies. He is committed to providing you with the latest insights and solutions to technology-related issues.

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