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Folder & ZIP Compare

Drop two folders or ZIP files on the left and right. The tool compares them by name and size, or by SHA-256 content, and lists files that are only on one side, that differ, or that were renamed with the same content. Save the result as CSV; files are not uploaded.

On-device・No uploadMobile friendlyWorks offline

Your files and input are processed only inside your browser on this device and are never uploaded to our servers.

Phone and tablet browsers may not support choosing or dropping folders. In that case, choose a ZIP with “Choose files”.

Left (older or source)

Nothing here yet

Drop folders, files or ZIPs here

or

Folders can be dropped whole. A ZIP is not unpacked to the screen; its contents are compared.
Right (newer or target)

Nothing here yet

Drop folders, files or ZIPs here

or

Folders can be dropped whole. A ZIP is not unpacked to the screen; its contents are compared.
How to compare

Name and size compares the size and date of files with the same path. Content calculates the SHA-256 of every file and compares them.

When off, Report.txt and report.txt count as the same name.

How to use

  1. Left: old folderFolder
    Right: backup.zipZIP contents

    Put in left and right

  2. Name, size, SHA-256Same content matches

    Match by name or content

  3. Result list (CSV)Changed, one side, moved

    List the differences and save

Match the left and right folders, list the differences, then save

  1. Drop folders, files or ZIPs on the left and on the right, or use “Choose folder” or “Choose files”. “Try a sample” creates two practice ZIP files.

  2. Choose how to compare. Name and size is fast; Content (SHA-256) reads every file, so it takes longer.

  3. Press “Compare”, then filter by result (left only, right only, different, same, renamed). Switch to “By folder” to see the files folder by folder.

  4. For a different text file, press “View differences” to see the lines that differ between left and right.

  5. Press “Save as CSV”. The CSV holds the result, paths, sizes, dates and SHA-256 values, not the file contents.

What it does

Compare by name and size, or by content

Choose name and size for speed, or content (SHA-256) for certainty. Comparing content also finds files with a different name and the same content, and lists them as renamed.

ZIP files compared without unpacking

The tool reads a ZIP’s directory to list its contents, and reads one entry at a time into memory only when it compares it. Nothing is unpacked to a folder.

Folder tree and list

See the count for each result, then switch between a list and a tree by folder. Change the case setting or search by path to narrow down to the files you need.

Line-by-line diff for text

Text files of 1 MB or less (.txt, .csv, .json, .html and so on) show the lines that differ between left and right side by side.

Separators and case handling

A backslash and a slash count as the same separator, so a ZIP made on Windows lines up with a folder. Upper and lower case can be matched exactly or not, as you choose.

Use cases

  • Compare a backup folder with the latest folder to find files that disappeared or changed
  • Check whether a delivery received as a ZIP matches the folder you hold
  • Find moved or renamed files by content, even when their names differ
  • List two document folders before you decide which one to keep

Supported formats

Input

Folders (dropped or chosen, including subfolders)Several filesZIP (.zip) contents

Output

CSV (UTF-8 with BOM, CRLF)

Capability matrix

FeatureSupportNotes
Comparing folders and ZIPs (left only, right only, same, different)Supported—
Content comparison (SHA-256) and detecting renamed files with the same contentSupportedEvery file is read, so large folders take time
Comparing name, size and dateSupportedDates within 2 seconds count as the same (ZIP and FAT precision)
Line differences in textPartialText files of 1 MB or less only. Images, Office documents and PDFs are not covered
Contents of a ZIPPartialZIP (.zip) only. 7z, RAR and tar are not supported
Comparing empty foldersNot supportedOnly the count is shown; they are not compared
Copying, syncing or deleting filesNot supportedThe tool only compares and never changes files
Comparing permissions, owners and attributesNot supported—
Choosing folders on a smartphonePartialDepends on the browser. ZIP files can always be chosen

Limits & notes

  • Up to 50,000 files and 20 GB in total per side. A side over the limit cannot be compared.
  • A file inside a ZIP larger than 256 MB is not hashed; it is shown as unreadable.
  • Content comparison reads every file in 8 MB pieces. Stopping in the middle gives no result.
  • Line differences are shown only for text files of 1 MB or less, and at most the first 1000 lines are displayed.
  • On smartphones and tablets, choosing or dropping folders may not work. In that case, choose a ZIP.

Privacy & safety

Reading, comparing and building the CSV all happen in your browser. File contents and names are never sent to or stored on a server.

FAQ

How do I compare two folders and see only the files that differ?
Put one folder on the left and one on the right, then press “Compare”. Choose “Different” in the result filter to see only the files whose content differs.
Can I compare a ZIP with a folder without unpacking the ZIP?
Yes. The ZIP is not unpacked to a folder. Its contents are listed from its directory, and each file is read into memory one at a time only when it is compared.
Can it find files that only changed their name?
Yes, with the content comparison. A file that has the same SHA-256 as a file on the other side is listed as “Renamed (same content)”. Name and size comparison cannot find them.
How are files that differ only in upper and lower case handled?
By default they count as the same name. Turn on “Match upper and lower case exactly” and they are listed as separate files.
Is my data uploaded?
No. Everything runs in your browser, and file contents and names are never sent to a server.

File Manifest

Load a folder and export a list of relative paths, sizes, modified times and types to Excel or CSV. Neither file names nor contents are uploaded. Use it for delivery lists, inventories, audits and backup records.

No upload

Duplicate Files

Load a whole folder and see groups of files whose content is byte-for-byte identical, with the space they waste. Nothing is uploaded and nothing is deleted: save the keep/duplicate verdicts as CSV or JSON and clean up with your own file manager.

No upload

Archive Studio — ZIP, TAR & tar.gz Viewer, Extractor & Creator

Drop a ZIP, TAR, tar.gz or gz to list what is inside — including ZIPs made on Japanese Windows whose file names are normally garbled. Extract safely, re-create a ZIP with UTF-8 names, or build a ZIP / tar.gz from folders. Everything runs on your device.

No upload

Batch Rename

Combine rules to rename files in bulk. Check old → new names live, catch duplicates and invalid names, then save renamed copies as a ZIP or into a folder. Files are never uploaded.

No upload

File Hash — Checksum Calculator & Verifier

Drop a file to get its SHA-256 (and more); paste the published hash to see match or mismatch instantly. Even multi-gigabyte ISOs are read in chunks on your own device — nothing is uploaded.

No upload

Universal File Inspector

Drop any file to see its real format (from the content), its structure and metadata, what to watch out for, and which tools can process it — before opening it, or before sending it to someone.

No upload

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