Ubigi eSIM in Japan Review (+5G Speedtests)

The first time I visited Japan was in 2018 when I went together with a friend of mine – Ditmar.

It was a hectic summer, as I also visited China a few weeks before and the Netherlands three times (before, between & after those trips – I was living in Denmark back then).

What surprised me is that the Japanese government banned the sale of voice-enabled SIM cards to travelers in 2006 for some reason.

As a result, only data-only SIM cards are sold to visitors like you and me.

Because VoIP (Voice over IP) apps like WhatsApp were already popular back then, it did not bother us that we could not make phone calls.

Since then, a lot has changed – travel eSIMs exist, and they are incredibly popular.

And I love trying them out to see which performs the best in individual countries like Japan.

So I revisited in 2023 and stayed in the Kansai Region (mostly Osaka) and Tokyo (again).

This resulted in me spending more than 480 USD for my Japan SIM card and travel eSIM review series (50 030 JPY (≈ 360 USD) on Japanese SIM cards and 121.50 USD on travel eSIMs to be used in Japan) – yeah… I went all out for you 😎.

I am excluding the cost of Airalo's Asialink 100 GB eSIM (185 USD) and its Discover Global 20 GB eSIM (89 USD) because I use both in multiple countries, not just Japan.

In many countries, getting a local SIM card will be the most cost-effective way to stay connected.

But that is not the case in Japan – they are criminally expensive.

Worse, almost all the Japanese SIM cards I tested had speed caps of 2 Mbps, 10 Mbps, or “unrestricted” speed for the first few days (often up to three days) before speeds would drop.

And I am talking about SIM cards that supposedly have no Fair Use Policy (FUP), and promise speeds up to 788 Mbps, or whose FUP I had not hit.

As a result, there is only one Japanese SIM card I recommend – but that one is expensive too.

Travel eSIM providers like Ubigi are way cheaper than Japanese SIM cards.

Even though it is powered by a Japanese mobile operator (NTT Docomo).

Surprisingly, they performed significantly better – even when roaming on the local networks.

This phenomenon is uncommon but happens in countries where mobile operators throttle (prepaid) speeds.

Because the Ubigi eSIM is basically cheaper than any Japanese SIM card available while having a significantly better performance than them, I can already recommend it if your phone supports eSIM.

Throughout this review, you will discover why I think this way, so let's start immediately!

Original publication: 18^th of June 2023. Last updated: 15^th of January 2024.

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Table of Contents

Which Phones are Compatible with Ubigi eSIMs?

Before discussing the Ubigi eSIM, you must know whether your phone can even support Ubigi's eSIMs.

Unlike most travel eSIM providers, Ubigi claims that every eSIM-compatible phone can use its eSIMs.

So that makes things easy 😎.

As of August 2023, the phones shown in the infographic below are compatible with Ubigi eSIMs:

With that out of the way, let's talk more about the Ubigi Japan plans!

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How Much Do Ubigi (Best) Asia Plans Cost?

You can get a Ubigi Japan plan for as little as 2.50 USD for 500 GB (1 day) up to 69 USD for 50 GB (30 days).

Note: once you have installed your Ubigi eSIM profile, you do not have to install another one in case you visit a different country (unlike most of its competitors, where you would have to install an eSIM per country, which is convenient!

Japan is one of the few Asian countries (with China, India, South Korea & Taiwan) where country-specific plans are available.

For the others, you need to get the Ubigi (Best) Asia Plans, which cover 14 (Best Asia) or 23 countries (Asia), for 6 USD for 500 MB (1 day) up to 49 USD for 10 GB (30 days).

But because Japan-specific plans are available, stick to them unless you plan on visiting nearby countries – more about Asia plans later.

Below is an overview of how much each Ubigi Japan plan costs:

1. Japan 500 MB plan for 1 day, costing 2.50 USD/2.50 EUR/2.50 GBP
2. Japan 1 GB plan for 30 days, costing 4 USD/4 EUR/3 GBP
3. Japan 3 GB plan for 30 days, costing 8 USD/8 EUR/7 GBP
4. Japan 10 GB plan for 30 days, costing 17 USD/17 EUR/16 GBP (price dropped – this is the one I used during this trip)
5. Japan 50 GB plan for 30 days, costing 69 USD/69 EUR/60 GBP

Clicking these links will get you to a page to generate a QR code to create an account (on mobile). You cannot buy any Ubigi plan on the front end (only on the back end), although I was promised you could in May 2023 (but it is June 2023 at the time of writing).

>>> Get your FREE Ubigi eSIM profile now! <<<

You can also get recurring plans for Japan.

In fact, Ubigi has three of them:

1. Japan 5 GB/month plan, costing 10 USD/10 EUR/9 GBP
2. Japan + United States 5 GB/month plan, costing 12 USD/12 EUR/10 GBP
3. Japan 20 GB/month plan, costing 29 USD/29 EUR/25 GBP

Yes, the Japan + United States can be used there too.

If your credit/debit card charges you foreign exchange fees, get yourself a Wise Borderless Account and Debit Card.

Their fees are MUCH lower than banks and credit card companies charge you (and Wise is transparent about their fees, unlike banks).

I have saved literal THOUSANDS of Australian Dollars and Euros, my main currencies, when using Wise abroad when traveling compared to my debit and credit cards.

Open a Wise account for FREE!

But you should be aware of the following for the recurring plans.

You need to stay on it for at least three months, meaning you spend at least 30/36/87 USD for the recurring plans.

It is not that Ubigi hides this fact – it is clearly mentioned on the purchase page (on the app).

But I thought I would let you know before buying the Japan 20 GB plan assuming the Japan 10 GB is too little while the Japan 50 GB is too much.

Finally, Ubigi has a long-term plan for Japan, giving you data for a year.

Yes, really – you can get the Japan annual plan for 38 USD, giving you 2 GB a month for 12 months (24 GB in total).

But you will pay this in advance at the time of purchase, so not 3.20 USD/2 GB/month.

Remember when I said there are also (Best) Asia plans that can be used in Japan?

What is the difference between the two plans, anyway?

The Asia plan can be used in 24 23 Asian countries (up to 1 GB (12 USD) unless you buy a recurring plan, then up to 5 GB (29 USD/month)).

Whereas Best Asia can be used in 12 14 East- and Southeast Asian countries only (up to 10 GB (49 USD)).

I will list the countries in a bit, but I do want to give you a price breakdown first:

1. Asia (23 countries) 500 MB for 1 day, costing 6 USD/6 EUR/5 GBP
2. Asia (23 countries) 1 GB for 30 days, costing 12 USD/12 EUR/10 GBP
3. Best Asia (14 countries) 3 GB for 30 days, costing 24 USD/24 EUR/21 GBP
4. Best Asia (14 countries) 10 GB for 30 days, costing 49 USD/49 EUR/45 GBP (this is the one I used during this trip)

If you wonder how I used both the 10 GB Japan plan and the 10 GB Best Asia plan, I still had some data left from my Best Asia plan from my visit to Singapore earlier. I eventually exhausted the data allowance for that plan, so I topped my eSIM up with the Japan plan.

Below is a complete overview of countries the Ubigi Best Asia plans work in:

¹ with 5G NR access (in Vietnam, select the Viettel network instead of the Vinaphone (VNPT) network for 5G NR access)

Below is a complete overview of countries the Ubigi Asia plans work in:

¹ on 3G only
² with 5G NR access (in Singapore, select StarHub instead of Simba Singapore for 5G NR access. For Vietnam, select the Viettel instead of Vinaphone (VNPT))

As you can see, the Japan-only plans are of better value if you only stay in Japan.

I have used my Ubigi eSIM in only two Asian destinations, besides Japan, which are Hong Kong and Singapore.

Those do not have country-specific plans (surprisingly), so I used the Best Asia in those countries.

>>> Get your FREE Ubigi eSIM profile now! <<<

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My Ubigi eSIM in Japan Experience

I used my Ubigi eSIM in Hiroshima, the Kansai region (mostly Osaka, but also Kobe, Kyoto & Nara) & Tokyo Metropolis (mostly Chiyoba City, but also Shinjuku City, Taito City & Yokohama City).

Before we continue, I do want to let you know how travel eSIM providers like Ubigi work.

It is impossible for Ubigi, or any other mobile operator, to operate in every country (and do not trust any company saying otherwise), so they set up roaming agreements.

And do not get worried by the word roaming yet – roaming can be expensive, but roaming with Ubigi or many other travel eSIM providers, will not result in a 5000 USD roaming bill.

What Ubigi does, and basically all (actual) mobile operators do, is partner up with a local mobile operator so that their customers can still stay connected when abroad.

In the case of Japan, the Ubigi eSIM uses the NTT Docomo with the help of… NTT Docomo.

I did not mention it yet, but Ubigi is a brand by NTT Docomo, so it makes sense its eSIM uses its network, lol.

The Japanese mobile operators are not in the prepaid business for whatever reason, so I mostly used Mobile Virtual Network Operators (MVNOs) using the NTT Docomo network through another MVNO called IIJmio.

All Japanese SIM cards I used using IIJmio were mostly/always throttled @ 2 Mbps, 10 Mbps, or would start off normally for the first (few) day(s) before being slowed as well.

I go more in-depth about that in my individual Japanese SIM card reviews, but all the travel eSIMs I used, including Ubigi, were not affected by this nonsense… so that was amazing 🤣.

So while I usually compare my eSIM results with the local mobile operator, it is not something I can do in Japan consistently because all the SIM cards I tried were MVNOs 🥲.

But worry not – I will do my best, mostly because I tried nine travel eSIMs using the networks of the Big Three (NTT Docomo, Softbank & AU by KDDI) with varying results.

When looking at 4G/LTE availability in Japan, the three mobile operators cover practically all of the country, with an availability of at least 99.4%.

Rakuten Mobile exists in Japan too, but tourists cannot get its prepaid SIM cards. Moreover, none of the SIM cards or eSIMs I used were using its network, so I will ignore its results in this analysis.

Japan's 4G/LTE reception is so good that you will unlikely be stuck on 3G at any time.

Unless you did not turn off airplane mode while taking off to send a quick message… I know who you are 😏.

In terms of 5G NR, Ubigi was the only travel eSIM I used with 5G NR access (COMST Japan was the only Japanese SIM card with such access).

In terms of speed, NTT Docomo has the fastest download speed, with a median download speed of 48.86 Mbps, ahead of SoftBank (44.77 Mbps) and AU by KDDI (41.60 Mbps).

But these results are somewhat similar, so you can say they have roughly the same speed.

The same can be said about upload speeds, where SoftBank is leading the pack (9.24 Mbps), followed by NTT Docomo (6.97 Mbps) and AU by KDDI (6.40 Mbps).

I did speed tests with the Speedtest app in three regions throughout Japan.

For reference, I consider an average download speed of 25 Mbps and an average of 10 Mbps upload speed fast enough.

Preferably, download speeds should be 100 Mbps+ on 4G/LTE… but we are not there yet 🗿.

But why these averages?

A download speed of more than 25 Mbps is enough to video stream content @ 4k resolution.

Social media sites that allow for live streaming, like Facebook Live, recommend an upload speed of at least 10 Mbps.

So, that is why – but that does not mean that a download speed of less than 100 Mbps excited me 😏.

But Australia spoiled… everything slower than 300 Mbps is slow now 🤣.

Anyway, you will also see that some of the results are in two shades of red, green, underlined, or in italics.

Underlined results are on 5G NR, while results in italics are on 3G.

The green shows that the result was the fastest on the network at said location.

For example, the Ubigi eSIM being the fastest travel eSIM on the NTT Docomo network in a mall.

While red shows that the result was the slowest on the network among its peers at the location.

Okay, that is enough background information – let's compare the Ubigi eSIM to other travel eSIMs primairly using the NTT Docomo network in Hiroshima, the Kansai region & Tokyo Metropolis.

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Ubigi eSIM Speed Test Results in Hiroshima

Hiroshima is mainly known for an incident that happened in 1945.

However, the radiation levels are so low nowadays that they are comparable to other Japanese cities – or most other cites worldwide.

Besides its history, it has much to offer, such as the Hiroshima Castle.

Including this cute variation of the castle.

Hiroshima on its own is worth visiting, although it can be a nice day trip or weekend getaway if you are in the Kansai region (Osaka) already.

While Hiroshima may or may not be among the ten largest cities in Japan (it used to be until the 2010 census – that is when it fell out of it), 5G NR was somehow not available in the city.

Ubigi and COMST Japan, an NTT Docomo Mobile Virtual Network Operator (MVNO), both have 5G NR access.

However, that technology was nowhere to be found throughout Hiroshima.

As a result, it was a leveling playing field to compare all the Japanese SIM cards and travel eSIMs I used because they all were on 4G/LTE.

For now, let's see how the Ubigi eSIM performed in Hiroshima:

>>> Get your FREE Ubigi eSIM profile now! <<<

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Ubigi eSIM Speed Test Results in the Kansai region (Kobe, Kyoto, Nara & Osaka)

While the term Kansai region may not ring a bell for some readers, it is the second-largest region in Japan (behind the Kanto region, which includes Tokyo Metropolis).

The Kansai region is home to the famous Osaka but also Japan's former capital Kyoto.

And a few others like Kobe (yes – the one from Kobe Beef) and Nara (with the large deer park).

Most tend to stay in Osaka when they are in the Kansai region.

But I would highly recommend visiting one of the cities I mentioned earlier because (1) you are nearby and (2) they are worth the visit!

Osaka and the Kansai region was my first destination during this Japan trip.

Here, I learned that most Japanese SIM cards are slow.

And I could not contribute that to me being in some remote town… because Osaka is Japan's third-largest municipality (behind Tokyo and Yokohama (south of Tokyo)) and it has 5G NR (which I used with Ubigi and COMST Japan).

Because Ubigi has direct access to the NTT Docomo network, because it is its sub-brand, I had a pleasant experience with it.

In fact, it was the best travel eSIM I used in the region.

So, let's see how the Ubigi eSIM performed in the Kansai region:

>>> Get your FREE Ubigi eSIM profile now! <<<

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Ubigi eSIM Speed Test Results in Tokyo Metropolis (Chiyoba, Shinjuku, Taito & Tokohama)

Tokyo, or the Tokyo Metropolis, probably does not need an introduction.

As you probably already imagining a bustling city with bright lights.

Which… it certainly is!

But do know that Tokyo consists of 26 cities (+a few towns and villages).

In fact, Tokyo Metropolis has 39 municipalities under its name.

This is why the heading for this section had Chiyoba, Shinjuku, Taito & Tokohama in parentheses because those are the cities I visited on this trip.

But wherever you go in Tokyo, you will have guaranteed fun 😄.

Let's see how the Ubigi eSIM performed in Tokyo Metropolis:

>>> Get your FREE Ubigi eSIM profile now! <<<

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My Overall Experience with the Ubigi eSIM in Japan – Is It Any Good?

I would recommend the Ubigi eSIM, and it would be one of my top recommendations for anyone wanting to buy a Japanese travel eSIM.

But… installing an Ubigi eSIM is a clumsy process.

Initially, you need to have cellular data enabled (on the Ubigi network).

After signing up, you are supposed to receive a code to confirm your details.

But you cannot submit your request for the code without enabling WiFi again (which the app does not tell you).

And if you are unlucky, the session times out, and you have to redo the registration process again.

Whereas other travel eSIMs have an easy and straightforward registration process.

But once the eSIM is installed, you no longer have to worry about this.

And getting a Ubigi plan, like the Japan plan, is straightforward.

Being expanded.

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Other Japanese eSIM Reviews (Airalo, Holafly, Japan Wireless, Nomad & SimCorner)

As mentioned earlier, I also tried out (other) eSIMs from Airalo (Moshi Moshi, Asialink & Discover Global), Holafly, Japan Wireless, Nomad (Japan and APAC) & SimCorner.

You should read those reviews too.

>>> Airalo Moshi Moshi eSIM in Japan Review | Airalo Asialink eSIM in Japan Review | Airalo Discover Global eSIM in Japan Review | Holafly Japan eSIM Review | Japan Wireless eSIM Review | Nomad eSIM in Japan eSIM Review | Nomad APAC eSIM in Japan Review | SimCorner Japan eSIM Review <<<