# Twins - Professional Duplicate Finder

Twins is a fast, elegant and precise duplicate finder for your Mac. It helps you to find unnecessary duplicates and get rid of them easily.

## Startup Window

When you open Twins you see the Startup Window. To select a folder for scanning, press the + button or drop it inside of the circle with the arrow. Hint: read more about scanning multiple folders in the How to Use section.

By default the scanning for your duplicates begins immediately (it can be changed in Preferences). Followed by the analyzation you're able to start browsing through the results by clicking the Show Results button. Hint: you're notified with a sound and the bounce of the app icon when the analyzation process is completed, so you can do other task during Twins analyzes larger folders.

## The Main Window

When the first duplicates show up during the analyzation, you're able to browse them in the main window.

### Duplicates by Size

The most important thing you want to know about your duplicates is their size, so you can get rid of the "big ones" quickly. The first column of the Main Window groups the duplicates in size ranges. The order of the size ranges depend on the total size of their content.

### Duplicate Groups

The second column lists the duplicate groups found during the scan. The size of a group equals the total size of it's files. The list can be easily filtered for certain file types (e.g.: mp3, m4a, mov, etc.) and sorted by size, duplicate count, name and selected item count. Use the check mark button to auto select duplicated items in the listed groups, and the X to deselect duplicates. Hint: read more about automatic selection in the How to Use section

### Duplicate items

The last column lists the files of the selected duplicate group. The upper part always shows the full path, the exact size and a preview of the item selected below. Use the checkbox to select certain files for removal, double click to reveal in finder.
Hint: click on the folder names in the full path bar to open a window with some basic information about the clicked folder and the folder based auto selection buttons.
The SHA-1 Checksum column displays a secure checksum for the files based on a cryptographic standard. If checksums are identical for two files it is very highly probable that they are exact duplicates. Read more about SHA-1 on Apple Support website. Folders have no checksum, if they are shown as duplicates it means their whole content is duplicated.
Note: Twins uses SHA-1 Checksum for comparing files, so only files with the same checksum are handled as exact duplicates. In case if Quick Scan is enabled similar files (possible duplicates) can show up in the results.
Read more about selecting and removing duplicate items in the How to Use section.

### Activity Panel

The panel in the bottom left corner displays current status information about the ongoing analyzation of your files. As long as the analyzation process is active you can expect new duplicate groups showing up. Hint: use auto selection when the analyzation is finished as it only works with the current result list.