(as) quick as a flash
Incredibly quickly or speedily. Did you see that martial arts master? His threw those kicks as quick as a flash! Quick as a flash, Mary finished her exam and raced out of the classroom.
quick as a flash
If someone does something or something happens as quick as a flash, they do it or it happens very quickly. Harrison responded as quick as a flash. Note: You can also say that someone does something or that something happens as quick as a wink or as quick as lightning. She kissed him right on the lips and then turned to go. Like that, quick as a wink. Rumours of his resignation flashed through the company as quick as lightning.
quick as a flash
(especially of a person's response or reaction) happening or made very quickly.(as) quick as a ˈflash
very fast or suddenly: Quick as a flash he replied that he had never seen it before.When the cat appeared, the bird flew away, as quick as a flash.