Frequently Asked Questions

Get instant answers to your questions and doubts


How do I use DupInOut Duplicate Finder?

We've provided a comprehensive User Manual with information about various program features, detailed steps and screenshots wherever possible. Please refer to the User Manual. You can also contact us at for assistance.

How are duplicate files identified?

DupInOut Duplicate Finder provides multiple ways to scan your files for duplicates:

  • File Content + Size: Use this option if you want to scan for 100% identical files. When you select this option, the program generates a hash of each file and compares it against the hashes generated of other files. Files with the same hashes are considered to be duplicates, and those with different hashes are considered as original files. In addition to the hash factor, it takes the file size factor into consideration. (A Hash is a fixed size string that represents original data inside your files. A hash has a fixed length value, and it is non-reversible. A file hash changes even if a single character was added, removed or replaced. To understand this process in detail and various types of hashing algorithms offered, please refer to the User Manual.)
  • Music Search: When selected, the software will analyze the music tags (metadata) of your music files to identify duplicate music. Music tags include various types of information embedded into your music files, for example, album, artist, bit rate, etc. If this information is not present, the software will either skip the file or compare the file's content, depending on your program settings. Read more about the Duplicate Music Finder feature or refer to the User Manual.
  • Similar Photos: Use this option to find visually-similar photos. DupInOut Duplicate Finder will compare the pixels of your photos to identify photos that have been rotated (up to 180 degrees), flipped (horizontal/ vertical), or converted from one image format to another. Read more about the Duplicate Photo Finder feature or refer to the User Manual.

How do I make sure that I don't accidentally delete an important file?

  • If you have inadvertently scanned folders that shouldn't have been scanned in first place, you can automatically exclude files from those folders. The Selection Assistant button provides options to exclude files from certain groups, folders, drives, apart from files matching the same name, file extension, etc.
  • Human errors are inevitable. To avoid potential data loss, you can choose the "Move to Folder" or "Rename Files" options. (Please note that "Replace with Shortcut" and "Move to Recycle Bin" options are specifically not recommended in this case. This is because "Replace with Shortcut" option overwrites your files with the .lnk Shortcut files. Besides, the "Move to Recycle Bin" option may sometimes permanently delete files that have longer file paths or a very large size, due to restrictions in Windows.

How do I exclude files from the Duplicates List after scanning them?

When you scan for duplicate files, you may not know which files will appear in the Duplicates List. The Excluded Files List feature allows you to automatically exclude a specific set of files from the Duplicates List. If you have any important files in the Duplicates List, you can exclude them from the results. Don't worry, if you think you have excluded a file by mistake, you can move it back to the Duplicates List again.

What is the Save Session feature? What does it do?

Consider a scenario. You started a duplicate scan and found a large number of duplicate files — in several thousands. The Save Session feature allows you to safely exit the application and re-load the same results later without re-scanning your files. This is helpful when you don't have sufficient time to review a lot of files. You can avoid the pain of re-scanning everything for another time.

Similarly, you can also run a long duplicate scan overnight and choose to automatically save session and shut down your PC or put it into sleep mode after completion. This way, you don't have to sit back for hours waiting for the entire scan process to complete.

What is the File Organizer feature?

File Organizer is an add-on feature that lets you re-organize files on your hard disk. Using the File Organizer, you can create unique folder structures and move/ copy your files. For example: You can re-organize files on your computer by their creation date in this format: D:\<File Creation Year>\<File Creation Month>\<File Creation Date>\<Your File>. You can create any pattern of your choice using the drop-down boxes. Keeping your files organized at all times will help you find a file when you need it the most — even if that means years later!

What is the Folder Compare feature?

DupInOut Duplicate Finder offers Folder Compare as an add-on feature. Folder Compare works uniquely. It compares the Source and Target folders in a hierarchical manner, whereas Duplicate Finder feature works in a non-hierarchical manner. Folder Compare compares files inside the Source and Target folders on a folder-to-folder basis and determines which files are the same, different (changed) and additional. To understand this process in detail with an illustration, please refer to the User Manual.

How do I view my scan history?

You can view your scan and action taken history from the My Activity dialog. Please note that your My Activity history is automatically deleted after a specific period of time to free-up your storage. You can disable automatic deletion or change the auto deletion time interval from the program settings.

Music Search

Is it possible that some music files may not have music tags?

Absolutely. Incomplete or incorrect music tags are often a reality. Some music files may not have the required music tags at all. If you’ve downloaded your music from a trusted, reputed website or store, it will likely have the music tags information. If the music tags information is not available, use the “File Content + Size” method to compare your files by calculating hashes. You can also manually edit the music tags information in batch using several freeware solutions.

What happens if a music file doesn't have music tags? Is it still scanned?

When you scan using the "Music Search" option, if a music file doesn’t have music tags information, such file will be skipped by default. However, you can change this behavior from the program settings. You can customize the program settings to analyze the file’s content and compare it with other music files with missing music tags information.

I am getting wrong or misleading results while using the Music Search

The accuracy of the Music Search feature largely depends on the music tags information embedded into your files. This information is typically edited by the website or store from where you downloaded your music. If the music tags information is incorrect, it will impact the accuracy of the results as well. You can use the "File Content + Size" method to identify duplicates by calculating their hashes.

Similar Photos Search

What are Same Photos and Similar Photos? How are they different?

Same photos are 100% identical copies of your photos. Similar Photos are identical copies of your photos with the same subject. However, similar photos have certain differences in terms of composition, size, image resolution, bit depth, color information, other objects in the photo, etc.

Can DupInOut Duplicate Finder identify both Same Photos & Similar Photos?

DupInOut Duplicate Finder can find both Same Photos and Similar Photos. You can find the same photos by using the "File Content + Size" method. Similarly, you can find similar photos using the "Similar Photos" method. Please note that at this moment, the program can identify similar photos that have been rotated (up to 180 degrees), flipped (horizontal/ vertical), or converted from one image format to another.

Is it possible to change the level of similarity while performing Similar Photos scan?

Absolutely. You can use the Similarity Threshold slider to change the level of similarity. However, we recommend keeping the default settings.

Free Trial

What is the 90-days fully-functional free trial? Are there any limitations?

You may use the DupInOut Duplicate Finder for free for 90-days with absolutely no limitations of any kind. You can fix UNLIMITED duplicate groups during your free trial period. However, once the free trial period is passed, a license is required to continue using the program.

Do I need to submit my email address, credit card or other private information to obtain a free trial?

Of course, not! We DO NOT ask for your email, credit card or other private information to start the free trial. You can try the program freely for 90-days and fix UNLIMITED duplicate groups and access all the program features. If you like it, you can purchase the program to continue using it after the free trial.


I didn't receive the License Key. What do I do now?

If you didn't receive the license key, please check your Spam/ Junk folder, and wait for a few minutes. If you still didn't get the license key, please contact us at We'll manually send you your license key.

How do I get back my License Key if I lose it?

Please drop us an email at from the email id you used during your purchase. We'll re-send you the lost License Key again at NO additional cost/ charges.

Do I have to purchase a new license if I change my PC?

Of course not. You can transfer your license from the old PC to your new PC. The process is simple and straightforward. First, uninstall DupInOut Duplicate Finder from your old PC. Drop us a support email at with the subject "Transfer my license to new PC" and mention your License Key in the email body. We'll reset your license from the server-side and your License Key will be released to be used on your new PC.

Errors & Known Issues

My License Key won't work

Your software licensing may fail due to one or more of the following reasons:

  • Your computer is not connected to the Internet. Please connect to the Internet.
  • Your Firewall software is blocking connection to the licensing server. Try disabling your Firewall software.
  • You're using the License Key on an ineligible device. For example, you're allotted the license for only single PC but you're trying to use it on a secondary PC. Only install the software on eligible devices, or request us to transfer your license to your new PC.
  • You're using the key on an unsupported operating system version. Please install the software on a supported operating system.

Please contact us at with the actual Error Code and we'll assist you with the same.

I think I have found a potential bug and I want to report it

We welcome reporting of potential bugs and problems as it helps to improve the software and fixes the issue even before someone else encounter it. Please contact us at We'll have a look at the issue.


I'm unable to drag & drop folders to the Search/ Ignore/ Organize Folders List

Normally, DupInOut Duplicate Finder runs on your computer without requiring special Administrator privileges. However, if you run it as Administrator, you may not be able to drag and drop folders/ drives to various lists. This issue occurs due to a security mechanism in Windows that blocks drag and drop functionality between an application running with special security tokens and an instance of File Explorer (formerly, Windows Explorer) running as a normal user. In Windows, both the application and File Explorer must be running with the same privilege to use the drag & drop functionality. In order to regain the drag and drop functionality, exit DupInOut Duplicate Finder and re-open it again as a normal user.

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DupInOut Duplicate Finder is a duly registered copyrighted work in accordance with the provisions of the Indian copyright law and is protected by the copyright law in India and other countries. Any unauthorized use, redistribution of this software and/ or its source code without prior written permission from the owner is strictly prohibited.

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