New in version 1.9.0.

caseSensitiveFS is an advanced folder setting that affects file name handling.

With caseSensitiveFS set to false (the default setting) Syncthing’s case sensitivity safety checks are enabled. Syncthing will then attempt to detect and prevent case-only file name collisions that can occur on case insensitive systems such as Windows and macOS, or other systems with case insensitive file systems.

When set to true the extra safety checks for case insensitive filesystems are disabled. This will provide a small improvement in performance when the underlying filesystem is positively known to be case-sensitive already. This was the behavior of Syncthing 1.8.0 and earlier.


This option should normally be set to false. It is not meant to change the basic principles of how Syncthing handles case-sensitivity.