Main menu > File

Standard menu entries in the File menu

	New	Ctrl-N	Creates new OSM data layer
	Open	Ctrl-O	Opens a file in a new layer
	Open location	Ctrl-L	Loads OSM data from an URL
	Save	Ctrl-S	Save the data in the current data layer to a file
	Save as ...	Ctrl-Shift-S	Save the data in the current data layer to new file
	Export to GPX ...	Ctrl-E	Export the current data layer as GPX file
	Download from OSM ...	Ctrl-Shift-D	Download data from the OSM server
	Download object ...	Ctrl-Shift-O	Download OSM object by ID
	Download parent ways/relations ...	Ctrl-ALT-D	Download ways including one of the currently selected nodes and relations referring to one of the currently selected objects
	Update data	Ctrl-U	Reload the bounding boxes in the current data layer from the server
	Update selection	Ctrl-Alt-U	Reload the currently selected objects from the server
	Update modified	Ctrl-Alt-M	Reload the modified objects in the current data layer from the server
	Upload to OSM	Ctrl-Shift-U	Upload new, modified, and deleted objects in the current data layer to the server
	Upload Selection to OSM	Upload new, modified, and deleted objects in the currently selected objects to the server
	Close open changesets	Ctrl-ALT-Q	Close open changesets
	Exit - Leave JOSM	Ctrl-Q	Exit JOSM

Additional menu entries in the file menu

Depending on the set of plugins you've downloaded and installed additional menu entries may be available in the file menu.