Default data directories

Firo-QT/firod

Blockchain and wallet.dat are stored here.

Windows: C:\Users\YOURUSERNAME\AppData\Roaming\firo
Linux: ~/.firo
MacOS:  ~/Library/Application\ Support/firo/

Flatpak (Linux only)

Blockchain and wallet.dat are stored here.

~/.var/app/org.firo.firo-qt/data

Electrum-Firo

Windows: C:\Users\YOURUSERNAME\AppData\Roaming\Electrum-FIRO
Linux: ~/.electrum-firo
MacOS: ~/.electrum-firo

Firo Masternode Tool

Windows: C:\Users\YOURUSERNAME\.firo-masternode-tool-v5
Linux: ~/.firo-masternode-tool-v5
MacOS: ~/.firo-masternode-tool-v5

Accessing the default data directory on MacOS

Open Finder, press Shift ⇧ + cmd ⌘ + G and enter /Users/YOURUSERNAME/Library/Application Support/firo