Kaunas is compact enough that you can cover the Old Town and Laisves aleja on foot. For anything further out, the city has an extensive public transport network of buses and trolleybuses — 47 bus routes and 16 trolleybus routes. Buy an electronic pass from kiosks near bus stops for convenience; single paper tickets are also available but cost more per ride.
Private minibuses (marshrutkes) supplement the main routes and run with impressive punctuality. Taxis are inexpensive but always confirm the per-kilometre rate before setting off. The city has dedicated bike lanes and several rental options — ask at the tourist information office for details. Car rental is available from international providers like Europcar, though you will not need one unless you are heading out of town.