There’s no definitive answer to whether or not firm or soft pillows are better, since it simply depends on your individual needs. Side sleepers and larger people generally prefer firmer pillows to ensure their heads and necks stay neutral. Some back sleepers also need firm pillows, but others may prefer something a bit softer to keep their spines neutral. However, stomach sleepers need softer or medium pillows to provide more cushioning for their necks and head.