The Robo Twist gets our highest rating for jar openers for a simple reason: It's the only device that easily opens containers ranging from, from a wide-mouthed pickle jar to small jam jars. It even works on big pasta sauce jars that, for some reason, was mission impossible for a very similar automatic device we found.
Here’s how it works: You place the pod containing the motor and two AA batteries (not included) on top of your jar and press the big green button on top. You keep the button pressed down as two outer arms with rubber grips move in toward the sides of the jar or bottle. Then you let go of the button as two inner arms move in to place rubber grips around the lid. Once that happens, the inner arms twist and—voila, every time—the lid opens, often with a satisfying pop. Then you wait a few seconds for the arms to reset to their original position.
The manufacturer says the Robo Twist should work on lids ranging from 1.2 inches to 3.5 inches across, and everything we tried was in that size range. It does not recommend using the device on plastic items, so you may need something else for those mayonnaise and peanut butter jars. The instruction manual suggests you lightly hold the sides of small or tall jars – presumably more prone to spillage – and that seems prudent, really, with any container.
While we can't speak to the average battery life of the Robo Twist, or how long it holds up to frequent use, we do know that after more than two dozen openings it was still going strong for us.
See more of the best jar openers.