Seven travel gadgets cover almost every trip: an unlocked eSIM phone, a 100-240V USB-C charger, a plug adapter, a power bank, wireless earbuds, a smartwatch and a luggage tracker. The harder part is not choosing products but knowing the conditions each one has to meet abroad. Voltage ratings, in-flight rules on radios and batteries, and smartwatch roaming requirements are all published by regulators and manufacturers. This guide goes through the seven gadgets one by one and checks each against official sources.
You do not need to rent a pocket Wi-Fi: one phone can handle your data. Browse the Coral eSIM plans and set one up for your destination before you leave.
Travel tech essentials come down to radio, power and in-flight rules
Most travel gadget lists are product roundups. What actually goes wrong abroad, though, is rarely a lack of features. It is a device that does not meet a condition. Those conditions fall into three groups.
- Radio: SIM lock on your phone, smartwatch roaming, Bluetooth use on board
- Power: the voltage your charger accepts and the shape of the plug
- In-flight rules: power bank capacity and quantity, and the ban on checked baggage
The seven gadgets below are ordered so you can check these conditions one at a time.
Travel tech essential 1: an eSIM phone with no SIM lock
Your phone is the hardest-working gadget on any trip. Maps, translation, ride-hailing, payments and boarding passes all live on it, so whether it connects to a local network decides how smooth the trip feels.
Check two things: that it supports eSIM, and that it is not SIM-locked. In Japan, a revised guideline from the Ministry of Internal Affairs and Communications means phones released on or after October 1, 2021 are, in principle, sold without a SIM lock. Older phones may still be locked.
On an iPhone, go to Settings, General, About. If "No SIM restrictions" appears next to Carrier Lock, you can use other carriers' SIMs and eSIMs. Apple notes that only your carrier, not Apple, can remove a lock. See how to check whether your phone is unlocked and how to check eSIM support.
Travel tech essential 2: a 100-240V USB-C charger
Outlets in Japan supply 100V, and many other countries use a higher voltage. Whether you need a voltage converter depends on the label on your charger.
Apple says its USB power adapters are designed for power sources rated at 100V to 240V AC, 50Hz to 60Hz. For other brands, if the "INPUT" line on the charger reads "100-240V", it works without a converter. Do not plug a device rated only for 100V straight into an overseas outlet.
A single charger with several USB-C ports is worth packing. It charges your phone, earbuds and watch together, and it saves you when the hotel room has few outlets.
Travel tech essential 3: a plug adapter for your destination
A charger that accepts the voltage is still useless if the plug does not fit. According to the International Electrotechnical Commission's World Plugs page, Japan uses Type A and Type B plugs at 100V and 50/60Hz. You can look up the plug type and voltage for your destination on the same page.
Some Apple chargers have a removable plug head, and Apple sells a World Travel Adapter Kit with seven interchangeable heads. For chargers with a fixed plug, use a standard plug adapter. Europe's plug types and voltage are covered in our Europe packing list.
Travel tech essential 4: a power bank whose Wh rating you know
Once you fly, your power bank falls under aviation rules. Japan's Ministry of Land, Infrastructure, Transport and Tourism (MLIT) set new rules from April 24, 2026: up to two power banks per person in the cabin, each 160Wh or less. Passengers must not charge a power bank on board, and must not charge other devices from one. Power banks cannot go in checked baggage and must not be stored in the overhead bin.
Capacity is usually printed in mAh, so convert it to Wh. MLIT gives the formula mAh × V ÷ 1,000: for example, 27,000mAh at 3.7V is 99.9Wh. If the label has worn off and you cannot read the capacity, there is no way to show it is allowed, so consider replacing it. Tips for travelers carrying more equipment are in what to pack for a business trip abroad.
Travel tech essential 5: wireless earbuds (Bluetooth on board depends on the aircraft)
Wireless earbuds make a long flight far more comfortable. Whether you can use Bluetooth on board, however, depends on the aircraft.
MLIT relaxed its rules on electronic devices in flight from September 1, 2014. On aircraft that tolerate radio emissions well (such as the B787, B777, A380 and A320), you can use Bluetooth earbuds or a mouse from takeoff to landing as long as your phone is in airplane mode. On other aircraft, use is restricted during some phases of the flight, such as around takeoff and landing. Once on board, follow the airline's guidance and the cabin crew.
The earbud case has its own battery too, so charge it before you go.
Travel tech essential 6: a smartwatch (cellular abroad comes with conditions)
Used alongside your iPhone, a smartwatch keeps notifications and payments working abroad. The part that needs care is cellular service on the watch itself.
According to Apple, international roaming on Apple Watch requires watchOS 9.1 or later, a cellular Series 5 or later, SE or later, or Ultra or later, and a carrier that supports VoLTE and roaming. The carrier decides which countries are covered. Apple Watch is also sold in regional models; there is no single worldwide model.
In other words, switching your iPhone to a travel eSIM does nothing for the watch's own cellular connection. If you want to use the watch on its own, confirm support with your carrier before you leave.
Travel tech essential 7: a luggage tracker you can share with airlines
A tracker such as AirTag in your suitcase or wallet lets you see where it is from your phone.
In November 2024, Apple added Share Item Location in iOS 18.2. It works on iPhone XS or later and lets you share a link showing an AirTag's location with an airline. The link expires after seven days at most. If your bag does not arrive, it gives you something concrete to show at the airport desk.
To send that link, your own phone needs to be online, so having data working when you land is part of making the feature useful.
Using gadgets bought abroad in Japan: the technical conformity mark
You may buy earbuds or a router on your trip. In Japan, Wi-Fi and Bluetooth devices generally need the "Giteki" technical conformity mark.
Article 4-2 of Japan's Radio Act provides that Wi-Fi and Bluetooth devices brought in by a person entering Japan, and meeting standards equivalent to Japan's, may be used for 90 days from entry. The ministry presents this mainly as a measure for visitors to Japan, and we could not confirm from official sources how it applies to Japanese residents who buy devices abroad. The safe choice is a device that carries the mark. Routers are covered in choosing an eSIM mobile router.
Travel tech essentials: frequently asked questions
Do I need a voltage converter when traveling abroad?
Not if your charger's label says "100-240V". Apple's power adapters are designed for 100V to 240V. Do not plug a device rated only for 100V straight into an overseas outlet. Use a plug adapter to match the outlet shape.
How many power banks can I take on a plane?
Under MLIT's rules from April 24, 2026, up to two per person, each 160Wh or less. They cannot go in checked baggage, and you must not charge the power bank or charge devices from it on board. Convert mAh to Wh with mAh × V ÷ 1,000.
Can I use wireless earbuds on the plane?
On aircraft that tolerate radio emissions well, such as the B787 and A320, you can use them from takeoff to landing with your phone in airplane mode. On other aircraft some phases are restricted, so follow the airline's guidance and the cabin crew.
Does Apple Watch cellular work abroad?
Yes, on a cellular Series 5 or later (or SE or Ultra) running watchOS 9.1 or later, if your carrier supports VoLTE and roaming. The carrier decides which countries are covered, so check before you leave. When paired with your iPhone, the watch still gets notifications through the iPhone's connection.
If I have an eSIM, do I still need a pocket Wi-Fi?
With an unlocked, eSIM-capable phone you can use a local network without renting a pocket Wi-Fi. To share data with a travel companion or a tablet, use your phone's hotspot. See eSIM vs pocket Wi-Fi for a comparison.
Check the official conditions for each travel gadget before you buy
With travel tech, confirming the conditions matters more than packing more devices. An unlocked, eSIM-capable phone. A charger labeled 100-240V. A plug adapter for your destination. A power bank with a known Wh rating, within the limit on quantity. Earbuds used according to the aircraft's rules. A smartwatch your carrier supports abroad. A tracker whose location you can share. Regulators and manufacturers publish every one of these conditions, so check them once before you buy and once before you pack. That is how you avoid carrying a gadget that will not work when you arrive.
For data, installing a travel eSIM on your phone before departure is all it takes. Choose a plan for your destination from the Coral eSIM plans.
