How to Use Your Smartphone While Traveling in Japan | Comparing SIM, eSIM, and Wi-Fi

While traveling in Japan, there are many situations where you will use your smartphone, such as checking Google Maps, navigating train and subway transfers, using translation apps, social media, and confirming hotel and flight reservations.

When moving from the airport to your hotel in Japan, if you can connect to the internet, you can quickly check transportation routes, travel times, and the hotel address.

Therefore, it is important to prepare a communication method that suits your travel style before your trip to Japan.

The main ways to use a smartphone in Japan are as follows:

• eSIM for traveling in Japan
• Prepaid SIM card
• Rental Wi-Fi

Each method differs in terms of how to receive it, ease of setup, luggage to carry, and how to use it with multiple people.

In this article, we will compare the differences between SIM cards, eSIMs, and rental Wi-Fi, explain who each is suitable for, the necessary data capacity for traveling in Japan, and important points to consider before use.

If you plan to use an eSIM, please check if your smartphone is compatible by referring to the list of eSIM-compatible devices before purchasing.

For communication plans for traveling in Japan, see here
→ View Japan eSIM products and pricing plans

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Three Ways to Use Your Smartphone While Traveling in Japan

1. eSIM for Traveling in Japan

An eSIM is a method of adding a communication plan in digital format to the SIM functionality built into your smartphone.

After purchase, you can use the QR code or setup information received via email to add it to your smartphone, so there is no need to swap out a physical SIM card.

If you purchase and set it up before your trip, you can turn on the eSIM line upon arrival in Japan and set up mobile data communication to access the internet.

The main advantages of Japan's eSIM are as follows:

• No need to swap physical SIM cards
• No need to pick up products at the airport or stores
• No need to carry a Wi-Fi router
• Can be purchased and set up online before the trip
• Easy to start communication immediately upon arrival in Japan
• You may be able to keep your regular SIM card in the device
• If you have a tethering-compatible plan, it can be used on multiple devices

This option is suitable for solo travelers, short trips, business trips, or temporary returns home who want to use the internet as easily as possible.

You can check the plans available for use in Japan on the Japan eSIM product page.

2. Prepaid SIM Card

A prepaid SIM card is a method of using a physical SIM card inserted into your smartphone's SIM slot.

In addition to purchasing online in advance, you may also be able to buy one at Japanese airports, electronics stores, or telecommunications company stores.

Even smartphones that do not support eSIM may be usable if the SIM size and supported frequencies of the device match.

Additionally, depending on the plan, you may be able to use a Japanese phone number, voice calls, and SMS.

On the other hand, you will need to swap SIM cards, and if you remove your regular SIM card, you must keep it safe during your trip to avoid losing it.

Prepaid SIM cards are suitable for the following people:

• Those whose devices do not support eSIM
• Those who are accustomed to using physical SIM cards
• Those looking for plans with a Japanese phone number
• Those who are comfortable with swapping SIM cards
• Those who want to purchase while consulting at a local store

Before purchasing, be sure to check the SIM lock, SIM card size, supported frequencies, and whether a phone number or SMS is included.

3. Rental Wi-Fi

Rental Wi-Fi is a method of connecting your smartphone, tablet, or computer to a dedicated mobile Wi-Fi router.

Since multiple devices can connect to one Wi-Fi router, it is easy to share communication during family or group trips.

On the other hand, you will need to pick up, carry, charge, and return the Wi-Fi router itself.

Additionally, if members of the group are going their separate ways, those without the Wi-Fi router will not be able to connect to the internet.

Rental Wi-Fi is suitable for the following people:

• Those who always travel together with family or a group
• Those who want to connect multiple smartphones or computers
• Those who do not want to change the SIM settings on their smartphones
• Those who are anxious about setting up eSIMs or SIM cards

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Comparing the Differences Between SIM, eSIM, and Wi-Fi

When comparing the differences between eSIM, SIM cards, and rental Wi-Fi available for use while traveling in Japan, it looks like this:

Advantages and Precautions of eSIM, SIM Cards, and Rental Wi-Fi

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What Communication Method is Recommended for Traveling in Japan?

For Solo Travelers or Short Trips, Choose eSIM

For solo travelers or short trips, eSIM is convenient as it does not require swapping SIM cards or picking up a Wi-Fi router.

If you complete the setup before departure, you can easily use maps, transfer guides, translation apps, and social media as soon as you arrive in Japan.

It is also suitable for those who do not want to carry a Wi-Fi router during their trip or want to minimize their luggage.

For Business Trips, Choose eSIM or SIM Card

On business trips, you may need to use email, business chat, online meetings, and tethering.

If data communication is the main focus, consider an eSIM; if you need a regular phone number or SMS, consider an eSIM or SIM card that supports voice calls and SMS.

If you need a phone number, please check the details of the eSIM with phone number.

For Temporary Returns, Choose a Long-Term eSIM

During temporary returns, your stay may be longer than a few days of travel.

In addition to short-term plans, it is reassuring to choose plans with longer available days, large capacity, or easy additional purchases.

If Your Device Does Not Support eSIM, Choose a SIM Card

If the smartphone you are using does not support eSIM, consider a prepaid SIM card.

Before purchasing, please check the following:

• Is the SIM lock removed?
• What is the SIM card size of the device?
• Does it support Japanese communication frequencies?
• What is the data capacity and usage period?
• Is there a phone number or SMS included?

For Family or Group Travel, Choose Rental Wi-Fi

If you want to share communication while moving together with family or a group, rental Wi-Fi is convenient.

Since multiple smartphones can connect to one router, it may be easier to consolidate contracts depending on the number of people.

However, if you plan to go your separate ways, you will not be able to communicate if you are away from the Wi-Fi router. Consider having each person use an eSIM or SIM card instead.

Recommended Communication Methods by Travel Style

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How Much Data Capacity is Needed for Traveling in Japan?

The amount of data capacity needed for traveling in Japan varies depending on the length of stay and how you use your smartphone.

If your main activities are maps, transportation searches, translations, and LINE, you may be able to get by with relatively low capacity.

On the other hand, if you frequently post photos or videos to SNS, watch YouTube, or use tethering, consider a large capacity plan or an unlimited type.

However, even plans labeled as unlimited may have speed restrictions applied after a certain amount of data is used. Be sure to check the conditions for high-speed communication and fair usage policies.

For more details, please refer to the data usage estimates.

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How to Set Up Japan eSIM

Setting up Japan eSIM generally follows these steps:

1. Purchase a Japan eSIM plan
2. Check the QR code or setup information received via email
3. Connect to a stable Wi-Fi environment
4. Add the eSIM from your smartphone's settings
5. Scan the QR code
6. Follow the on-screen instructions to install
7. Turn on the eSIM line after arriving in Japan
8. Select the Japan eSIM for mobile data communication
9. Turn on data roaming if necessary
10. Turn off Wi-Fi and check the connection

Please use a stable Wi-Fi environment when installing the eSIM.

If you are displaying the QR code on the same smartphone, the camera on that device will not be able to scan it. Display the QR code on a computer, tablet, or another smartphone to scan it.

For detailed setup instructions for iPhone and Android, please refer to the eSIM setup guide.

How to Start Using eSIM After Arriving in Japan

If you installed the Japan eSIM before departure, you will perform the following settings after arriving in Japan.

1. Turn on the Japan eSIM line
2. Select the Japan eSIM for mobile data communication
3. Turn on data roaming for the Japan eSIM
4. Set network selection to automatic
5. Turn off Wi-Fi
6. Open a browser or map app to check the connection

If you set up the Japan eSIM outside of Japan, it may display "Out of Service" or "No Service" until you arrive in Japan.

After arriving in Japan, you may be able to use it by connecting to the appropriate network, so please check the line settings and data roaming.

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Precautions When Using eSIM in Japan

Check if Your Device Supports eSIM

To use eSIM, your smartphone must be compatible with eSIM.

Even with the same model name, it may not support eSIM depending on the country of sale, carrier, or model number.

Please check the list of eSIM-compatible devices before purchasing.

Check for SIM Lock

If your device has a SIM lock, you may not be able to use the travel eSIM.

Check the SIM lock status from your carrier or the smartphone's settings screen.

Check the Timing for Starting Use

The timing for when the eSIM becomes active varies by plan.

• Starts when the eSIM is installed
• Starts when connected to a Japanese network
• Becomes active from the specified start date

If you set it up too early, the usage period may start before your trip. Be sure to check the instructions after purchase.

Do Not Delete the eSIM

If you delete an eSIM that has been added, you may not be able to reconfigure it with the same QR code.

If you cannot connect, do not delete the eSIM immediately; check the line settings, data roaming, APN, etc.

Be Careful with Data Roaming on Your Main Line

If data roaming is turned on for your regular main line, you may incur overseas roaming charges.

Select the Japan eSIM for mobile data communication and turn off data roaming for your regular main line as needed.

Be Aware of Automatic Switching of Data Communication

On dual SIM-compatible devices, mobile data may automatically switch from the Japan eSIM to the main line depending on the communication status.

If you want to avoid unintended overseas roaming, turn off the automatic switching of mobile data communication.

Data-Only eSIMs Do Not Allow Regular Phone Calls or SMS

General travel eSIMs are for data communication only.

With a data-only eSIM, you cannot use regular phone numbers for voice calls or send/receive SMS.

However, you can use internet-based calling and messaging apps like LINE, WhatsApp, and Messenger.

If you need a phone number, voice calls, or SMS, please check the eSIM plan with phone number.

Check Tethering Compatibility

Whether tethering can be used with eSIMs or SIM cards depends on the plan and device.

If you plan to share communication with a computer or tablet, please check the product page before purchasing.

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What to Do If Japan eSIM Does Not Connect

If you cannot connect with the eSIM after arriving in Japan, check the following items before deleting the eSIM.

1. Check if the Japan eSIM line is turned on
2. Check if the Japan eSIM is selected for mobile data communication
3. Turn on data roaming for the Japan eSIM
4. Turn off Wi-Fi and check the connection
5. Turn airplane mode on and then off
6. Restart your smartphone
7. Check if APN settings are needed
8. Set network selection to automatic
9. Check the start date and validity period
10. Check if you have exhausted your data capacity

A common issue is that the Japan eSIM is installed, but a different line is selected for mobile data communication.

Additionally, with travel eSIMs, you may need to turn on data roaming for the Japan eSIM side.

If checking the settings does not resolve the issue, do not delete the eSIM; prepare your order number, device name, OS, settings screen, error messages, etc., and contact support.

For more details, please refer to the troubleshooting guide for Japan eSIM.

For contact information, please check Japan eSIM support.

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Frequently Asked Questions About Communication Methods for Traveling in Japan

Can I Purchase eSIM After Arriving in Japan?

If you have access to the internet, you may be able to purchase online even after arriving in Japan.

However, you will need a communication environment to purchase, check the QR code, and download the eSIM. Since airport and hotel Wi-Fi can be unstable, it is safer to purchase and set up before your trip.

Which is Recommended for Traveling in Japan, eSIM or Wi-Fi?

For solo travel or trips with many separate activities, eSIM is recommended; for family or group travel where everyone moves together, rental Wi-Fi is suitable.

However, rental Wi-Fi requires carrying, charging, and returning the router. If you want to reduce your luggage, each person can also use an eSIM.

Which is Cheaper, eSIM or SIM Card?

Prices vary depending on the number of days used, data capacity, supported countries, and whether a phone number is included.

Be sure to compare not only the product price but also the costs for pickup, return, call charges, SMS fees, and additional data charges.

Can I Use a Phone Number with Japan eSIM?

The available features depend on the plan.

With a data-only plan, you cannot use voice calls or SMS with a regular phone number.

If you need a phone number, please check the eSIM plan with phone number.

Can I Use LINE or WhatsApp with Japan eSIM?

If data communication is available, you can use LINE, WhatsApp, Messenger, and other messaging and internet calling apps.

How Many People Can Use Rental Wi-Fi?

The number of devices that can connect depends on the rental Wi-Fi router used.

Connecting multiple devices simultaneously may affect communication speed and battery consumption, so check the supported number of devices before applying.

What Communication Method is Recommended for Temporary Returns?

If you are using an eSIM-compatible device, a Japan eSIM that matches your length of stay is convenient.

For long stays, check the number of available days, total data capacity, the possibility of additional purchases, and tethering compatibility.

What Happens If I Delete Japan eSIM?

You may not be able to reinstall it with the same QR code.

If you accidentally delete it, check with support to see if a new QR code can be issued.

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Conclusion | Choose a Communication Method That Fits Your Travel Style in Japan

There are three ways to use your smartphone while traveling in Japan: eSIM, prepaid SIM cards, and rental Wi-Fi.

Each has its advantages, but it becomes clearer to choose based on the following criteria:

• Solo travel/short trips: eSIM
• Devices without eSIM support: SIM card
• Family/group traveling together: rental Wi-Fi
• Business trips: large capacity eSIM or plans with phone numbers
• Temporary returns: long-term eSIM

For those who want to use the internet easily during solo travel or short trips, eSIM is convenient as it does not require swapping SIM cards or picking up and returning a Wi-Fi router.

JAPAN&GLOBAL eSIM offers Japan eSIM plans that can be used for travel in Japan, business trips, and temporary returns.

Check your travel days, required data capacity, the necessity of a phone number or SMS, and plans for tethering, and choose the communication method that suits you.

View Japan eSIM Plans ›

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