Some restaurants operate on a no-tipping policy in which taking care of the staff to offer a living wage is factored into the overall price of the food. Others may automatically include gratuity when the bill is drawn. If either of these instances is the case, then no, you do not need to tip on top of this price. However, if the service was exceptional and you had a wonderful experience, an additional tip is never a bad idea.
If you’re at an establishment that provides no way for you to leave an extra tip, besides leaving cash on the table — and by the way, who has cash these days? — there are other ways you can thank the staff. Leave a great review online, call the manager over and tell them how amazing the experience was, or buy a round of shift drinks for the staff.
The service industry is a tough profession, if you had a great experience, gestures of gratitude go a long way.