There are two types of can openers, manual and electric, and each have advantages and disadvantages. Manual can openers consist of two arms and a hand crank that must be turned to operate the opener. They are easier to store (most fit nicely in a kitchen utensil drawer) but can be more difficult to use than electric can openers, especially for people with arthritis or limited manual dexterity.
Electric can openers operate with the flip of a lever or push of a button and are usually faster than manual models. Most electric can openers are designed to sit on a countertop, although some can be mounted under a cabinet. Depending on how tall the unit is, however, some electric can openers may not be able to accommodate larger cans. Cordless automatic can openers, meanwhile, occupy a middle ground between traditional electric can openers and manual ones. They use batteries, rather than plugging into an outlet, and many are only slightly larger than manual can openers, making them easy to store.
You should also consider the kind of cut that the can opener makes -- along the side of the can or the top of the can. Traditional top-cut openers allow you to leave the lip slightly attached to the can so you can drain liquids from fruits and vegetables. However, top-cutters leave sharp edges around the lid, a potential safety hazard. Side-cut openers generally don't leave sharp edges, cutting beneath the lip of the can. Some reviewers like these models because they leave an intact lid that you can replace for storage, but this also makes draining liquids very difficult.
The best review of electric can openers we found is conducted by Wired. Three handheld electric can openers and one countertop model are compared. This brief review considers each automatic can opener in terms of balance, speed and cleanliness, pointing out advantages and disadvantages of each model. However, the products are not ranked, so it's difficult to tell which can opener is the best.
The best professional review of manual can openers we found comes from Cook's Country magazine, which reviews eight models priced under $20. Testers evaluate each can opener for safety, ease of operation and comfort, although specific ratings for each category aren't provided. The article also doesn't specify how testing was conducted. Each of the openers is either recommended, recommended "with reservations" or not recommended. Of the eight models tested, four are recommended.
We also found useful consumer reviews of can openers, both manual and electric, at Amazon.com, Cooking.com, Viewpoints.com, Walmart.com and Target.com. Consumer reviews for kitchen appliances are often valuable, because owners can attest to the longevity and functionality of products, whereas formal testing offers limited insight into durability under continued wear and tear.
One can opener receiving mixed reviews is the battery-powered One Touch Can Opener (*Est. $20). With the push of a button, the One Touch travels around the edge of the can, producing a side cut that is not supposed to leave sharp edges. A magnet grabs the lid to prevent it from falling into the food.
Carol and Richard Eustice, About.com's guides to arthritis, include the One Touch Can Opener in their list of six arthritis-friendly can openers, but there's no evidence of how they tested this model or compared it to other can openers. (Note: ConsumerSearch is owned by About.com, but the two don't share an editorial affiliation.) Meanwhile, reporter Kevin Kelly of Little Rock, Ark., station KLRT compares the One Touch to a manual and an electric can opener to see which is the fastest; the One Touch was the slowest of the three. Despite this, Kelly says the One Touch Can Opener works adequately. Lori Price also reviews the One Touch Can Opener in an article for the Milwaukee (WI) Journal Sentinel, and reports that it doesn't live up to its claims, however.
Most of the user reviews we found for the One Touch Can Opener are also less than flattering. Almost 200 owners on Amazon.com award the One Touch Can Opener an average rating of only 2.5 stars out of five, and more than 80 rate this product with only one star out of five. Owners say the batteries tend to die partway through opening a can, leaving the unit stuck to the lid and nearly impossible to remove. Reviews on Walmart.com are more positive; the One Touch Can Opener has an average rating of four stars out of five, based on over 100 reviews. Most reviewers are pleased with the hands-free operation of the One Touch Can Opener, but there are also a number of complaints regarding the unit becoming stuck on a lid partway through removal. More than 30 owners review the One Touch Can Opener on Target.com, and feedback is mixed.