Stay Connected in Japan: Finding the Perfect eSIM for Your Australian Phone

A trip to Japan, how exciting! Delicious food, beautiful scenery, unique culture... a wonderful experience awaits. What can be a bit troublesome during your trip is smartphone internet connectivity. 'I want to see a map,' 'I want to check train times,' 'I want to send photos to friends and family!' It's inconvenient when you can't use the internet at times like these. There are several ways to use the internet overseas, but recently, what's particularly popular and recommended is the 'eSIM'.

In this article,

• Can your Australian smartphone be used in Japan? (Talk about frequencies)
• Why is eSIM convenient for travel?
• Recommended eSIMs in Japan (especially the docomo network)

we will explain these clearly!

Can Your Smartphone Be Used in Japan? Thorough Comparison of Australian and Japanese Frequencies

You might wonder, 'Can I use the smartphone I use in Australia as is in Japan?' The answer is 'Yes', but depending on the SIM card or eSIM you purchase to communicate in Japan, you might not be able to connect. What's important here is 'frequency'.

What is Frequency? Why is it Important?

For a smartphone to connect to the internet using radio waves, it uses something like 'paths' decided by each country and mobile phone company. These 'paths' are called 'frequency bands' or 'bands'.

If the frequency bands used in Australia and the frequency bands used in Japan do not match, the smartphone cannot catch the radio waves. That's why it's important to know if your own smartphone supports Japan's frequency bands.

Australia's Major Carriers and Japan's Frequency Compatibility Chart (4G/LTE)

First, let's look at the '4G (LTE)' frequencies, which you will likely use most often. We have summarized in a table which Japanese carrier's 4G frequency bands are compatible with smartphones from Australia's main carriers (Telstra, Optus, Vodafone).

(Note: There are also frequency bands like B7, B40, etc., used in Australia but not used in Japan)
(〇: Widely compatible, △: Compatible only with some carriers)

Looking at this table, you can see that major frequency bands like Band 1, Band 3, and Band 28 can be used with most Japanese carriers, regardless of which Australian carrier's smartphone you have!

Conclusion: It's highly likely that your smartphone is fully compatible with Japan's 4G/LTE network! With this, you can use it in Japan with peace of mind.

What About 5G?

Next, let's also look at the faster '5G'.

(Note: There are also incompatible frequency bands like n5, n1, n40, n258, etc.)
(〇: Compatible carriers exist)

Regarding 5G, the frequency band n78 can be used with Japan's docomo and KDDI(au). If you have a Vodafone smartphone, it might support even more of Japan's 5G bands.

However, there are points to note.

1. Does the smartphone itself support that 5G band?: It depends not only on the carrier but also on whether your smartphone itself can catch Japan's 5G bands.
2. Japan's 5G area is still limited: 5G is not available everywhere in Japan; it's mainly centered in urban areas (as of April 2025).

Conclusion: While there's a possibility of using 5G, it might still be a bit difficult for travelers to expect consistently comfortable 5G connections. It's better to assume that communication during your stay in Japan will primarily be centered around the stable 4G/LTE network.

Reasons Why eSIM is Definitely More Recommended Than Physical SIM for Japan Travel

Now that you understand the compatibility with Japanese frequencies, the next step is how to connect to the internet. What's recommended here is the eSIM!

eSIM has many advantages that traditional plastic SIM cards do not.

• No need to swap SIM cards!: Just download the SIM information (profile) to the smartphone body. There's no worry about losing or breaking small SIM cards. No SIM pin is needed either.
• Completed online!: You can purchase and set it up online via websites etc., either in Australia before your trip or immediately after arriving in Japan. No need to go to a store.
• Usable immediately!: Once setup is complete, you can connect to the Japanese network right away. You can look at maps or make contact as soon as you arrive at the airport.
• Can be used as Dual SIM: If your smartphone supports it, you can use Japanese data communication via eSIM while keeping your Australian SIM card inserted. You can also receive calls coming to your Australian phone number (depending on settings).

Considering the hassle of swapping SIM cards or renting and carrying a Wi-Fi router, eSIM can be said to be a very smart and convenient option.

Connection in Japan is Mainly Centered on 4G/LTE

As mentioned earlier in the frequency discussion, considering the current communication environment in Japan, the 4G/LTE network becomes the main way for travelers to use the internet stably.

Of course, you might be able to experience the speed of 5G if you're lucky in urban areas, but considering travel to rural areas or during transit, you will mostly be connected to 4G/LTE, which covers Japan widely.

Therefore, when choosing an eSIM, it's recommended to prioritize 'whether 4G/LTE can be used stably' rather than 'whether 5G can be used'.

【Conclusion】For Short-term eSIM Use in Japan, the 'docomo Network' is Recommended!

There are several mobile phone companies in Japan, but if you are choosing an eSIM for travelers, plans that use the 'docomo network' are particularly recommended.

Reasons to Choose the docomo Network:

1. Widest Area Coverage Rate in Japan: docomo has the widest communication area in Japan. Its major strength is that signals reach easily not only in large cities like Tokyo and Osaka but also in rural tourist spots and even slightly mountainous areas. There is a sense of security that 'it connects easily wherever you go'.
2. Stable Communication Quality: It is a network used by many people, and its communication quality is stable and highly rated.
3. Compatibility with Australian Smartphones is also Excellent◎: docomo fully covers Japan's major 4G/LTE frequency bands (such as Band 1, 3, 19/26, 28, etc.). As seen in the previous table, Bands 1, 3, and 28, which Australian smartphones support, are included, so connectivity compatibility is good.

How to Choose a Short-term eSIM Plan Using the docomo Network

Even when saying 'docomo network eSIM', various companies offer plans. The points for choosing are as follows.

• Data Allowance: Choose according to how much internet you will use. If it's mainly for maps and searching, a smaller amount might be fine, but if you watch videos or upload many photos, a plan with more allowance (e.g., 10GB, 20GB, etc.) would be better. Unlimited plans may also be available.
• Usage Days: Choose according to the number of days you will stay in Japan. There are plans for various durations, such as 5 days, 7 days, 15 days, 30 days, etc.
• Price: The price changes depending on the data allowance and usage days. Let's compare several services.
• Ease of Purchase and Setup: It's reassuring to check things like whether the website is easy to understand or if there is a support system.

If you choose these eSIMs, you should be able to enjoy the internet without stress during your trip to Japan using docomo's wide and stable network!

Summary

The trip from Australia to Japan, exciting isn't it!

• Your smartphone is likely compatible with Japan's 4G/LTE frequencies.
• As a communication method, the easy and convenient 'eSIM' is recommended.
• If choosing an eSIM, it's reassuring to select a plan that uses the 'docomo network', which connects easily throughout Japan.

If you prepare the eSIM in advance, you can use your smartphone immediately upon arrival in Japan, making the start of your journey smoother. Please utilize eSIM and enjoy a smart and comfortable trip to Japan!