reflac
Recompress FLAC files in-place while preserving metadata. tldr-pages
On several platforms
Several platforms
Recompress a directory of FLAC files
reflac path/to/directoryIdentifyEnable maximum compression (very slow)
reflac --best path/to/directoryIdentifyDisplay filenames as they are processed
reflac --verbose path/to/directoryIdentifyRecurse into subdirectories
reflac --recursive path/to/directoryIdentifyPreserve file modification times
reflac --preserve path/to/directoryIdentify