Tram 12 is a real time commitment — fit it in only if it's a priority.
Allow 25–35 min loop.
Same vintage carriages, much of the same tilting Alfama scenery, but a tight loop most tourists overlook in favour of the famous 28. The catch: it covers less ground and skips Estrela/Chiado, so it's a scenic taste rather than a tour. Still the smart move if you mainly want the tram experience without the crush.