# 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.

- URL: https://tools.itlibra.com/en/folder-compare
- On-device・No upload
- Last updated: 2026-10-23

## How to use

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.

## 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

## 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.


## Supported formats

### Input

- Folders (dropped or chosen, including subfolders)
- Several files
- ZIP (.zip) contents

### Output

- CSV (UTF-8 with BOM, CRLF)


## Capability matrix

| Feature | Support | Notes |
| --- | --- | --- |
| Comparing folders and ZIPs (left only, right only, same, different) | Supported | — |
| Content comparison (SHA-256) and detecting renamed files with the same content | Supported | Every file is read, so large folders take time |
| Comparing name, size and date | Supported | Dates within 2 seconds count as the same (ZIP and FAT precision) |
| Line differences in text | Partial | Text files of 1 MB or less only. Images, Office documents and PDFs are not covered |
| Contents of a ZIP | Partial | ZIP (.zip) only. 7z, RAR and tar are not supported |
| Comparing empty folders | Not supported | Only the count is shown; they are not compared |
| Copying, syncing or deleting files | Not supported | The tool only compares and never changes files |
| Comparing permissions, owners and attributes | Not supported | — |
| Choosing folders on a smartphone | Partial | Depends 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.