Some countries, such as the U.S., Canada and the Caribbean, have electrical outlets that generally supply 110 volts of electricity while Europe, New Zealand and Australia have outlets with 220 volts. Plugging a 110 appliance in a 220 outlet could fry it. Some appliances come with built-in converters. You can also buy a converter but few work for all appliances for all countries. Some travel advisers recommend you use transformers instead.
Compact converters pack easily and are relatively cheap. But many don't work with items that create heat, like blow dryers or flat irons. Others aren't safe for computers. And the plug configuration for Ireland or Britain is different from other parts of Europe. World Travel Guide recommends the Automatic Combination Voltage Converter which does work with appliances that heat up to 2000 watts. A more versatile device is the Universal 3-in-1 Adapter, Converter, and USB charger which has both plug configurations and many types of outlets including a USB outlet. But the 3-in-1 does not offer surge protection.
Best for Heated Appliances
The Automatic Combination Voltage Converter works for heating with appliances up to 2000 watts, which is one of the highest ratings and uses a Euro two-pronged plug. However, the Lite Fuze voltage converter works for up to 1600 watts and includes plugs that can get you plugged in while visiting one of 150 countries.
Best for Computers
Most laptops have internal converters that should keep your computer safe. However, according to John Bermont, author of "How To Europe," if you really want to be sure, a transformer is safer than a converter. Transformers provide protection against power surges. Lite Fuze sells one that is about 7X10X6 which is much bulkier than a converter or conversion kit. But it's grounded, which many converters aren't. It can handle up to 2,000 watts, so it works with heated appliances. And it has four output sockets.
Best for No Heat
The Walkabout is very small, less than 2 X 2 X 2 inches, has built-in adapters for every country except India and South Africa and has many options for plugging in including a USB port. Recommended by World Backpackers, it is not rated for heated appliances such as blow dryers or heating pads. It is fuse protected for power surges, meaning if the power does surge, it will blow a fuse and shut down. It is also thermal protected against overheating, a common problem with converters.