Search for a duplicate-file-finder and you’ll find yourself bombarded with junkware-filled installers and paid applications. We’ve put together lists of the best free duplicate-file-finders so you can save some time.

The applications here cover Windows, Mac OS X, Linux, and even Android. Apple’s iOS doesn’t offer a user-visible file system, so you can’t do this on an iPhone or iPad. No Chrome apps are currently available to do this on a Chromebook.

Windows

RELATED: How to Find and Remove Duplicate Files on Windows

The biggest problem when searching for a duplicate-file-finder for Windows is all the junkware. There are many different duplicate-file-finder apps that probably work okay, but want to force various toolbars, search engine changes, and other junkware onto your system when you install them. There are also paid applications that you don’t really need to buy because freeware will work just fine for you.

We liked the dupeGuru applications for this, but Duplicate File Finder offers more basic and potentially faster scanning, DigitalVolcano’s Duplicate Cleaner Free is decent if you want a commercial application that gives you a prettier interface at the cost of a few nag screens. VisiPic works well for hunting down duplicate photos with a nice visual interface.

Read our detailed overview of the best duplicate-file-finders we found for Windows to find out which is right for you. None of these programs will try to install junkware on your system.

Mac

RELATED: How to Find and Remove Duplicate Files on Mac OS X

Mac OS X has a richer paid software ecosystem, so there are many good paid duplicate-file-finder apps with slick interfaces. High-quality paid apps like Gemini are primarily available in the Mac App Store and work fairly well.

You’re better off downloading from their website, however, because they make a free trial available there. If you like it, then you can upgrade to the paid version for all of the features.

The Mac App Store doesn’t provide a way for developers to give away demo or trial versions of their apps, however. Many app developers do offer demos, but the demo versions must be downloaded from their websites and installed the old-fashioned way.

If you don’t want to spend money on this, the cross-platform and open-source dupeGuru is also a good option for Mac users. It doesn’t have the pretty interface you get if you spend money on a paid Mac app, but it will absolutely do the job. Really, dupeGuru stands out on Mac as the only free duplicate-file-finder we found. We did stumble across some older applications, but we weren’t about to recommend unsigned applications that haven’t been updated in years.

iTunes also has a built-in feature that can find duplicate songs, so this can help you save space if you have a big, unwieldy local music files with duplicate songs.

Take a look at our overview of the best duplicate-file-finders for Mac OS X to find the right tool for you.

Linux

RELATED: How to Find and Remove Duplicate Files on Linux

Linux doesn’t have problems with toolbar junkware or paid apps. The main problem you’ll face on Linux is that most of the available tools are barebones command-line utilities. It’s fairly easy to write a little script that uses built-in Linux commands to scan your file system, compare files, and find duplicates — you could even string together commands to do this on your own.

There are still good, mature applications for finding and removing duplicate files on Linux. FSlint offers a good graphical interface and should be available in most Linux distributions’ software repositories. fdupes is a great command-line tool you’ll find in most distributions’ software repositories for easy installation. dupeGuru is also available for Linux, thanks to being cross-platform and open-source — however, it’s not in most Linux distributions’ software repositories and takes a bit more work to install.

Check out the best duplicate-file-finding tools we found for Linux. You won’t find the shiniest interfaces, but you will find simple, functional software that doesn’t want to push junkware on you or sell you anything.

Android

Android has a user-visible file system, so it’s no surprise there are duplicate-file-finder apps available in Android’s Google Play store. These apps will scan your device’s SD card — or the internal flash storage that emulates an SD card — for duplicate files and offer to remove them. Such apps won’t touch system files or most app data, but they will find duplicate photos, music, videos, and other files you may have copied to your Android phone or tablet.

We tried Search Duplicate File(Super) — the most popular duplicate-file-finder app in Google Play at the moment — and found it worked fine. Like many older Android apps, it has a Gingerbread-style interface and isn’t all that pleasant to use. However, its basic interface is fitting for a system tool that most people wouldn’t really need. Even if you do need this tool, you probably only need to run it once to give a cluttered SD card a cleanup, so the interface shouldn’t be too obnoxious.

RELATED: Android's App Permissions Were Just Simplified -- Now They're Much Less Secure

On Android, the main thing you need to watch out for are apps that abuse the permission system to track you and upload data about you to advertising servers. As a free app, Search Duplicate File(Super) has the basic system-scanning permissions it needs as well as the Intenret access it requires to display ads — like many free Android apps. Many Android apps will probably do a decent job of this — just be sure to mind the permissions.

If you have duplicate files in a cloud service like Dropbox, Google Drive, or OneDrive, you could also those files to a Windows, Mac, or Linux PC and use one of the tools above to scan for and remove duplicate files.