Types
4 kinds of electric toothbrush
The type decides the head you will be buying for years, how the brush feels in the mouth, and whether you charge it at all. It says little about how well it cleans; see the evidence explainer for what is and isn’t known.
Sonic
30 models from 7 brands, ~$20–$380
Sonic brushes vibrate an elongated head side to side at high frequency, and makers quote the figure freely: 26,000 to 84,000 a minute across this catalog. Those numbers are each maker's own unit and are not comparable across brands. Most sonic handles here use a rectangular head held at the gumline and swept along the teeth.
Oscillating-rotating
12 models from 2 brands, ~$40–$330
Oscillating-rotating brushes use a small round head that cups one tooth at a time and turns rapidly back and forth; Oral-B's models add pulsation or micro-vibrations. You guide the head slowly from tooth to tooth rather than scrubbing. Makers of these brushes rarely publish a speed (Oral-B gives none for its US iO range), so the comparisons here lean on sensors, modes and running cost instead.
Kids
6 models from 5 brands, ~$18–$45
Kids' brushes differ from adult ones mainly in head size, bristle softness and a starting age the maker states, which runs from 2 to 6 across this catalog. Two run on AAA batteries, so a lost charger is not a problem. None of the kids' models here lists a pressure sensor.
Battery & slim
4 models from 3 brands, ~$16–$40
These are the brushes built around never needing a charger: a single AAA that the maker says lasts up to three months, or a slim rechargeable with a month or more between charges. They are light, cheap and easy to travel with, and they give up pressure sensors, modes and screens to get there.