What is the voltage in Japan and will my devices work?

Japan's household electricity is 100 V, lower than most countries, and this guide shows how to read device labels so phones, laptops and hair dryers stay safe.

Published October 21, 2026 at 9:02 AM JST | By Tokyo Paul

Quick answer: Japan's household voltage is 100 V, lower than the roughly 120 V used in North America and the roughly 230 V used in Europe, the UK and Australia. Most phone, tablet and laptop chargers accept 100 to 240 V and work with only a plug adapter. Hair dryers, irons and other heating devices may not, so check each label.

The answer: 100 V, nationwide

The Japan National Tourism Organization (JNTO) states that the voltage used throughout Japan is uniformly 100 volts, alternating current. That figure applies from Hokkaido in the north to Okinawa in the south. Wikipedia's article on mains electricity by country lists 100 V as Japan's standard household supply, with 200 V also used for some higher-power and industrial equipment.

For comparison, North America typically uses about 120 V, while Europe, the United Kingdom, Australia and many parts of Asia use roughly 220 to 240 V. Japan sits below both groups. That means devices made for higher-voltage countries may receive less power than they expect, and devices from North America will see a small drop.

Voltage is only one part of the picture. Plug shape and, in a few cases, electrical frequency also matter. The good news is that modern electronics are usually designed to work across many countries, so for most travelers the whole question comes down to reading one line of text printed on each device.

How to read a label in under a minute

Turn the charger or device over and find the small print near the plug. Look for a line reading "INPUT" followed by numbers. If it says something like "100-240V ~ 50/60Hz", the device is dual voltage and works in Japan with just a plug adapter if the plug shape differs. Most phone, tablet, camera, e-reader and laptop chargers carry this wide range.

If the label shows a single value, such as "120V" or "230V", the device was built for that voltage only. A 120 V device can often run on 100 V, although it may perform slightly weaker, run warmer or not reach its full performance. A 230 V device is a more serious mismatch, because at 100 V it may not start or may work poorly.

Also check the wattage or amperage on the label. Devices that draw a lot of power, such as hair dryers, may exceed what a travel converter can handle. If you are unsure, the manufacturer's customer service or manual can confirm whether a model is intended for use at 100 V. When in doubt, leave the device at home or buy a suitable one locally.

Everyday devices: what usually works

Smartphones, tablets, smartwatches, wireless earbuds, e-readers, cameras and laptops almost always come with chargers rated for 100 to 240 V. With these, the only thing to solve is the plug shape. Power banks charge from the same type of adapter, so they behave the same way. Battery chargers for cameras are also usually universal, but a quick label check is worthwhile.

Small electric toothbrushes and shavers vary. Many modern rechargeable models use a universal charging base, while older or cheaper ones may specify one voltage. Check the base or the manual. Similarly, portable speakers and game consoles often use external power bricks that state their range, so the label on the brick is the one that counts.

For larger items such as a travel kettle, a curling iron or a straightener, read the label and the manual. Some are dual voltage with a switch or automatic detection, while others are fixed. A dual-voltage model is marked on the body or the plug, and it is the easiest way to avoid trouble when you travel to multiple countries.

Hair dryers, irons and heating devices

JNTO notes that dual-voltage hair dryers, travel irons and shavers should work anywhere in Japan, while other devices may need a step-down transformer. Heating devices draw high power, so voltage mismatches show up quickly: a dryer built for 230 V can feel weak at 100 V, and a converter that cannot handle the wattage may overheat. Single-voltage heating devices are the category most worth rechecking.

Many hotels in Japan provide a hair dryer in the room or on request, which is the simplest solution. Policies differ by property, so check the hotel's listing or ask before arrival. A hotel dryer also removes the need to pack something bulky and avoids the risk of damaging a personal device through a voltage mismatch.

If you do carry a heating device, use only a converter or transformer rated well above the device's wattage, and never run it unattended. Heating elements and converters can get hot, so keep them away from bedding, curtains and bathroom water. Buying an inexpensive travel dryer in Japan, if needed, is another easy option for longer stays.

Who should be extra careful

Travelers from Europe, the UK, Australia, New Zealand and much of Asia, where mains voltage is around 220 to 240 V, face the largest gap. Their chargers are often universal, but older single-voltage appliances are not. Checking each item before packing prevents surprises, and it keeps luggage lighter because the items that cannot be used can stay at home.

Travelers from North America have an easier time because 120 V devices usually work on 100 V, though sometimes with reduced performance. Anything with a motor or a heating element may feel less powerful, and some devices with sensitive timers or clocks may drift. A short test charge at the hotel on the first night shows whether each device works as expected.

People who depend on medical or mobility equipment, such as a sleep apnea machine, an insulin cooler or a wheelchair charger, should ask the manufacturer in advance about 100 V use. This guide shares general information, not professional advice; for health concerns, talk with a doctor or local clinic. The equipment maker or supplier can also advise on backup power.

Three easy errors with voltage

The first mistake is using a plug adapter and assuming that it handles voltage. Wikipedia's article on plugs and sockets states that adaptors do not change voltage or frequency, and a voltage converter is a separate device. An adapter only changes the shape of the pins so that the plug fits the wall socket, nothing more.

The second mistake is buying a cheap converter for a high-wattage device. Hair dryers and curling irons can draw more power than small travel converters are built to supply. The converter may overheat, trip or fail. The converter's rated wattage must exceed the device's wattage by a comfortable margin, and many travelers choose to leave such items home instead.

The third mistake is ignoring the label because the device "worked last time" in another country. A device that handled one country's voltage may not handle another. A related slip is forgetting power strips and extension cords, which must also be rated for the local voltage and the load, and should be checked like any other item.

A simple routine before and after arrival

Before the trip, gather all electronics and make a short list sorted into three groups: universal chargers that need only a plug adapter, single-voltage devices that need a converter or replacement, and items better left at home. Photographing each label with your phone makes it easy to check later in a shop or hotel room.

Once in Japan, large electronics stores in cities sell adapters and transformers, as JNTO notes, and hotel desks can often help with simple questions. When buying a device locally, look for products made for the Japanese market, which are designed for 100 V and 50 or 60 Hz and avoid mismatches.

Keep a small pouch for chargers, a short extension cord or a compact power strip, and a spare cable. Charging overnight at the bedside works best when cables are long enough to reach the outlet, and a pouch makes packing up in the morning faster and reduces the chance of leaving something behind.

Frequently Asked Questions

Is 100 V dangerous for foreign devices?

Not usually. Lower voltage tends to mean weaker performance rather than damage, especially for devices built for 120 V. Devices built for 220 to 240 V are the larger concern. Check the label for a range that includes 100 V, or ask the manufacturer.

Can a phone charger from Europe be used in Japan?

Often yes, because many chargers carry a 100 to 240 V rating. The plug shape is the usual obstacle, so a small plug adapter is typically needed. Confirm that the label shows a range that includes 100 V before plugging in.

Do Japanese hotels have hair dryers?

Many do provide one in the room or on request, though this varies by property. Checking the hotel's listed amenities before arrival is a reasonable step. Relying on a hotel dryer can save luggage space and avoid voltage problems with a personal one.

Want to go deeper? Tokyo Paul's book Tokyo Info Guide is available on Amazon.

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