Berean Standard Bible (BSB)
The creatures were darting back and forth as quickly as flashes of lightning.
World English Bible (WEB)
The living creatures ran and returned as the appearance of a flash of lightning.
Strong's King James
And the living creatures{H2416} ran{H7519}{(H8800)} and returned{H7725}{(H8800)} as the appearance{H4758} of a flash of lightning{H965}.
The F.O.G *
The F.O.G Message *
Young's Literal Translation
And the living creatures are running, and turning back, as the appearance of the flash.