Supergirl airs Mondays @8pm on The CW, The Flash in the same time slot on Tuesdays, Arrow on Wednesdays, and Legends of Tomorrow on Thursdays.
The Flash episode received 4.25 million viewers and was the show’s most-watched since season 1’s ‘The Man in the Yellow Suit’ (the episode that followed The Flash’s first crossover with Arrow).
Meanwhile, Arrow’s crossover episode delivered the show’s most-watched episode since last year’s crossover with 3.55 million viewers.
However, Legends of Tomorrow perhaps benefitted most from the crossover, earning its most-watched episode ever with 3.39 million viewers.