# Comparison Settings

## Symbolic Link Handling

FreeFileSync lets you choose to include symbolic links (also called symlinks or soft links) when scanning directories rather than skipping over them. When included, you can select between two ways to handle them:

1. Follow: Treat symbolic links like the object they are pointing to. Links pointing to directories are traversed like ordinary directories and the target of each link is copied during synchronization.
2. Direct: Evaluate the symbolic link object directly. Symbolic links will be shown as separate entities. Links pointing to directories are not traversed and the link object is copied directly during synchronization.

Note

- Under Windows the symbolic link options apply to symbolic links, volume mount points and NTFS junction points.
- Copying symbolic links requires FreeFileSync to be started with administrator rights.

## I. Compare by file time and size

This variant considers two files with the same name as equal when both modification time and file size match. The following categories are distinguished:

1. file exists on one side only
   - left only
   - right only
2. file exists on both sides
   1. different date
      - left newer
      - right newer
   2. same date
      - equal
      - conflict (same date, different size)

## II. Compare by file content

Two files with the same name are marked as equal if and only if they have the same content. This option is more useful for consistency checks rather than backup operations since a bitwise comparison can be slow.

1. file exists on one side only
   - left only
   - right only
2. file exists on both sides
   - equal
   - different content

## III. Compare by file size

Two files with the same name are considered equal if they have the same file size. Since it's possible for files with the same size to have different content, this variant should only be used when file modification times are not available or reliable, e.g. in certain MTP and FTP synchronization scenarios.

1. file exists on one side only
   - left only
   - right only
2. file exists on both sides
   - equal
   - different size