When it launched in 2012, Uber’s original stance on tipping drivers was that it would make using the app more of a hassle for drivers and passengers. “In the end, we decided against including one because we felt it would be better for riders and drivers to know for sure what they would pay or earn on each trip — without the uncertainty of tipping,” the company wrote in a 2016 blog post in response to two class-action lawsuits.

After public pressure and complaints from drivers, Uber ultimately decided to change its policy in July 2017. Competing apps like Lyft had launched by that time with the option built-in, and Via and Juno also allow riders to tip their drivers.

How much should you leave ?

Brett Helling is a former Uber driver who now owns and runs Ridester.com, a resource for drivers. Mr. Helling said he tips drivers between 10 and 20 percent the cost of the trip, based on the level of service. Julia Boyd, an international etiquette consultant, agreed. For U.S. rides , she recommends tipping between 15 and 20 percent for exceptional service, 10 to 15 for good service, and 10 percent for average service.

“Many Uber trips can be more expensive than a standard cab. However, a standard cab offers a standard service. Uber drivers will often have exceptionally clean cars and fresh water for their passengers,” Ms. Boyd said.