Where Does Arduino Store Sketches and Board Cores?
Arduino splits user files between a Sketchbook folder and a hidden Arduino15 folder. Sketch, library and board-core paths for every OS.
Last updated
Arduino IDE keeps your work and its own machinery in two different places. Sketches and user libraries live in the Sketchbook, an ordinary visible folder in Documents. Board cores, toolchains and the package index live in Arduino15, a hidden folder whose exact spot depends on the OS.
Knowing which is which settles most Arduino file questions. Lost sketches mean the Sketchbook path changed; missing boards mean Arduino15 got wiped or the Store variant renamed it to ArduinoData. A full clean reinstall means removing both folders plus the IDE itself, since uninstallers leave your files behind.
Where Arduino IDE stores this, by platform
%USERPROFILE%\Documents\Arduino
Sketches save here by default with .ino extensions; libraries go in the libraries subfolder. Board cores live separately at %LOCALAPPDATA%\Arduino15. The Windows Store build names that second folder ArduinoData under Documents instead. Sketchbook location is changeable in File, Preferences.
~/Documents/Arduino
Board cores live at ~/Library/Arduino15. Open it via Finder's Go, Go to Folder, since Library is hidden. Sketchbook location is changeable under Arduino IDE, Settings. IDE 2 also keeps UI state in ~/.arduinoIDE and ~/Library/Application Support/arduino-ide.
~/Arduino
Board cores live at ~/.arduino15, hidden by the leading dot. Sketchbook location is changeable in File, Preferences. IDE 2 also keeps UI state in ~/.arduinoIDE and ~/.config/arduino-ide; deleting the latter two fixes many startup hangs without touching sketches.
Frequently asked questions
where do i put arduino libraries manually
Inside the Sketchbook's libraries subfolder. The Library Manager installs there, and hand-added libraries go in the same place as folders containing a .h file and examples. Restart the IDE after adding by hand. Libraries bundled with board cores live in Arduino15 instead and should be left alone.
why did my boards disappear after reinstalling arduino
You deleted the Arduino15 folder or the board core it references. Reinstall the board package through the Boards Manager and the core downloads fresh. Your sketches are safe; they live in the Sketchbook, which is a different folder entirely.
how do i move the arduino sketchbook folder
Open Preferences and change the Sketchbook location field. The IDE uses the new folder for saves, libraries and manual hardware cores from then on. Move your existing sketches and libraries folders across yourself; changing the setting does not move files.
Notice an outdated path? Let us know.