The Bose Portable Smart Speaker is our only portable smart speaker, while the Bose Home Speaker 300 and Smart Speaker 500 have no battery and must be plugged into the wall to function. Acoustically, the Portable Smart Speaker and the Home Speaker 300 have comparable performance, with the same 360-degree sound and impressively rich bass from similarly compact sizes. Meanwhile, the larger Bose Smart Speaker 500 is our best-sounding smart speaker, providing wall-to-wall stereo sound from a single enclosure. The Smart Speaker 500 also includes a display screen to show you what’s playing. Finally, the Portable Smart Speaker is water-resistant and does not have an aux input, while the Home Speaker 300 and Smart Speaker 500 are not water-resistant and do include aux. All three speakers share the same app and software features, including compatibility with the Bose Music app, Apple AirPlay 2, Bluetooth, the ability to synchronise in multi-room groups and more.