The quartet smashed the previous record of 18 hours and 31 minutes with their epic trek on Saturday, reported Swiss media including 20 Minuti.
Riccardo Khoyi, aged 15, Romano Gatto, 18, and brothers Dominic and Pascal Pini, 23 and 17 respectively, set off from Bellinzona station at 6.13 on Saturday morning and arrived at St-Maurice in the Valais at 23.32 having travelled over 1,000km by bus and train, changing 24 times.
The friends were aiming to enter the Guinness Book of Records and in July applied to make the record attempt, reported Blick.
They documented their journey on Facebook, taking pictures of themselves at each rail station they visited, holding up a picture of the relevant cantonal flag.
Thankfully, Swiss trains were typically punctual on Saturday, meaning the boys' record attempt wasn't stymied by delays, said Blick.
In Lucerne they only had one minute to change trains – but they made it.
Their record attempt was helped by the new Gotthard Base Tunnel, which has made the journey from Ticino to Uri a lot faster than when the previous record was set, said 20 Minuti.
Not only did they travel through all 26 Swiss cantons but they did it without spending much money. Two of them already had an AG/GA which allowed them to travel anywhere in Switzerland, while the other two bought a 40-franc day pass from their commune.
The quartet must now send through their documentation to Guinness for validation, Dominic Pini told The Local.