Shorter front and rear overhangs and a more steeply raked windscreen create a streamlined profile.
As before, the roof is made from fabric, but it now sits exposed behind the cockpit when lowered.
The interior gets a smart centre console fitted with an 18cm colour touchscreen.
Porsche says the inspiration for the layout came from the Carrera GT hypercar sold from 2004 to 2006.
The changes continue under the bonnet, with the entry-level 2.9-litre flat-six replaced by a 2.7-litre unit.
Despite the downsizing, power has climbed by 7kW to 195kW.
The Bosxter S sticks with its 3.4-litre flat-six but gains an extra 4kW, taking its total to 232kW.
Both engines are fitted with stop-start. Performance has taken a small jump. The Boxster accelerates from 0-100km/h in 5.7 seconds - a tenth of a second faster than the old car - while the Boxster S takes exactly five seconds, an improvement of two tenths.
A six-speed manual is fitted as standard. However, both cars achieve their best performance and fuel consumption with the optional seven-speed PDK gearbox.
Porsche claims fuel figures with the seven-speeder of 7.7 litres/100km for the Boxster and 8 litres/100km for the Boxster S.
Standard kit on the Boxster includes a remote control hood operation and the touchscreen. The Boxster S adds Xenon headlights.
To enhance driving, Porsche offers dynamic transmission mounts for the first time.
Also new on the roadster is Porsche Torque Vectoring (PTV) with mechanical rear axle differential lock.
