You could but we don’t advise you to try it. A lot of online blackjack games automatically reshuffle during hands so as a card counter, you have no benefits. You’re just wasting your time. What you should do if you’re playing online blackjack is to check with the variation that possesses the lowest house edge. Study that variation and find the strategy that would work best for it. Because that is the only way you can get an advantage in this game.