Duplicate File Finder

Find byte-identical files in a folder and see how much space they waste.

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Choose a folder

Read in this tab. Nothing is uploaded, and the page cannot see anything outside what you pick.

How to Find Duplicate Files in a Folder

Photos copied twice from a phone, the same PDF saved into three project folders, a music library imported on two different laptops. Duplicates pile up quietly and eat disk space you paid for.

This finder reads the folder you pick and compares every file by its actual contents. Two files only count as copies when every single byte matches, so a renamed copy is caught and two different files that happen to share a name are left alone.

It gives you a list to work from, not a delete button. You stay in charge of what goes, and nothing in the folder leaves your computer while it is being checked.

No software to install Free Works on any device

Steps to Spot Identical Files

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1. Choose a folder

Click the box and pick the folder you want checked. The page shows how many files it found and their combined size. Subfolders inside it are included.
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2. Press 'Find duplicates'

A progress bar runs while the files are compared. Only files of exactly the same size are fingerprinted, which is why a large folder still finishes quickly.
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3. Read the groups

Each group shows how many identical copies exist, the size of one copy and how much space you would get back. One path is marked KEEP and the rest DUPLICATE.
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4. Delete the extras yourself

Open the folder in File Explorer or Finder and remove the copies you do not need. The page cannot delete, move or rename anything.

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What Is a Duplicate File Finder?

It is a checker that tells you which files in a folder are exact copies of each other. This one works out a SHA-256 fingerprint for every file that shares its size with another. Matching fingerprints mean matching contents, down to the last byte.

Because names and dates are ignored, 'IMG_2041.jpg' and 'IMG_2041 (1).jpg' are paired up if they hold the same picture. An edited or resized photo is a different file, so it is not reported.

Why Use File and Archive Tools?

A ZIP from a colleague, a download with no extension or a folder full of badly named files can stop work for a while. These tools unpack, identify, hash and rename files inside your browser, so nothing is uploaded to find out what it is.

“Know what a file is before you open it.”

Archives opened without software
Downloads checked with hashes
Duplicate files found
Big files packed smaller

Unknown files identified
Files renamed in bulk
Folders compared quickly
Contents never leave your computer

Popular Uses for ZIP and File Tools

These tools help with the small file puzzles that come up every week.

Opening RAR files See and extract what is inside an archive on a computer with no unzip program.
Checking a download Compare a file’s SHA-256 checksum with the one on the download page.
Mystery files Find the real type of a file that has lost its extension or has the wrong one.
Renaming photos Rename a folder of camera photos with dates or numbers in one go.
Clearing duplicates Find repeated files taking up space in a downloads or photos folder.
Sending many files Pack several documents into one ZIP so they travel as a single attachment.
Comparing folders See which files differ between a backup folder and the working copy.
Reading file details Check a file’s size, dates and hidden metadata before sharing it.

What the Duplicate Checker Shows You

Content matching, not name matching

Files are compared by SHA-256 fingerprint, so only true byte-for-byte copies appear in the results.

Space you can recover

A banner totals the wasted space across every group, and each group shows what deleting its extra copies would free.

Largest waste first

Groups are sorted by how much room they waste, so big video duplicates sit at the top and tiny icons at the bottom.

Read-only by design

The browser only gets permission to read the folder you chose. It cannot see anything outside it and cannot change a single file.

Why Use ToolXkit for Duplicate File Finder?

Your files stay with you

Everything runs inside your browser. Nothing you open or type is uploaded to a server.

Archive Tools for Different Users

Office workers

Open ZIP attachments and bundle reports together without extra software.

Developers

Check signatures, MIME types and hashes, and create TAR or GZIP files.

IT support staff

Identify strange files and verify downloads before installing anything on a machine.

Photographers

Rename shoots in bulk and find duplicates before backing up a card.

Students

Unpack course material and zip up project folders for submission.

Security-minded users

Check what a file really is before trusting its name or icon.

Best Times to Unpack or Check a File

File tools are useful when you are:

Opening an archive on a new computer
Verifying a software download
Stuck with a file that won’t open
Tidying a messy downloads folder
Emailing a folder of documents
Checking a backup is complete
Renaming lots of photos
Freeing space on a full drive

Tips for Cleaning Up Duplicates

The KEEP label simply marks the first path found. Read the full paths and keep the copy stored where you actually look for it.
Use a computer for this. Picking a whole folder is a desktop browser feature, and many phone browsers only let you choose single files.
Check a parent folder, such as Pictures, rather than two subfolders one at a time. Copies that live in different subfolders are only paired when both are inside the folder you pick.
Empty the Recycle Bin or Trash afterwards. Deleted duplicates keep using the disk until you do.
Be careful inside program or system folders. Some apps keep identical files on purpose and break when one is removed.

Frequently Asked Questions

Answers to common questions about this tool.

Does this find similar photos, or only exact copies?

Only exact copies. A photo that was cropped, resized, filtered or saved again at a different quality has different bytes, so it counts as a separate file. That strictness is what makes the list safe to act on.

Can the tool delete the duplicates for me?

No. The page only has permission to read the folder you picked, so it cannot delete, move or rename anything. Use the list of paths and remove the extra copies yourself in File Explorer, Finder or your file manager.

Are my files uploaded anywhere?

No. The browser reads the files on your own computer and works out their fingerprints there. No copy goes anywhere, which is why it is fine to point it at a folder of private documents or family photos.

Why did nothing appear after I pressed the button?

If no two files in the folder share exactly the same size, there is nothing to compare and no groups can appear. That means the folder holds no duplicates. Try a larger parent folder if you expected some.

How big a folder can it handle?

That depends on your device. Only same-size files are read in full, so most folders go quickly, but a folder with many large videos of equal size takes longer because each one has to be read from start to finish.

Can I open a RAR or 7z file without installing anything?

Yes. RAR Viewer and 7z Viewer show what is inside and let you save the files you need, all from the browser. This helps on office computers where you cannot install an unzip program.

What is a checksum and why check one?

A checksum is a short code worked out from a file’s contents. If your copy gives the same code as the one the publisher lists, the file arrived complete and unchanged.

Is there a size limit in Duplicate File Finder?

It depends on your device rather than on the site. Everything is processed in memory in the browser, so a computer handles bigger archives and folders than a phone does.

Is Duplicate File Finder free to use at work?

Yes. It is free for personal and work use with no account. Because files stay on the machine, it also fits workplaces that do not allow uploading documents to outside sites.

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