Internet Archive has it online:
Variety says, "it is interesting every minute of the way." 1000 Misspent Hours says, "it’s one of the earliest movies of its type that still survives" and that West strikes a
workable balance between (actual) horror and (mostly notional) humor, while giving his new movie a striking and memorable look that incorporates many of the innovations of the German Expressionists. It goes wrong in places, to be sure, but The Bat holds up astonishingly well across the ages.
Weird Wild Realm says, "For years this silent film was presumed forever lost, until a single copy in excellent condition resurfaced" and adds
Its influence on the Old Dark House motif in cinema cannot be overstated, whether for good or bad. It may also be an unacknowledged but primary influence on the gothic look of Bob Kane's original Batman comics, & even the familiar Bat Signal is present in this film!