The first time I visited Japan was in 2018 with my friend Ditmar. That summer was hectic, as I had already visited China a few weeks prior and the Netherlands three times (before, between, and after these trips – I was living in Denmark at the time).
One surprising discovery was the Japanese government's ban on the sale of voice-enabled SIM cards to travelers since 2006. As a result, only data-only SIM cards are available for visitors. This restriction was not a major issue for us, given the popularity of VoIP (Voice over IP) apps like WhatsApp.
Fast forward to 2023, I revisited Japan, spending time in the Kansai Region (mostly Osaka) and Tokyo.
With the advent of travel eSIMs, I was eager to test their performance in Japan. This endeavor resulted in an extensive review series, costing me over 480 USD. Note that this amount excludes the cost of Airalo's Asialink 100 GB eSIM and its Discover Global 20 GB eSIM since I use these in multiple countries.
In many countries, a local SIM card is the most cost-effective way to stay connected. However, this is not the case in Japan, where SIM cards are notoriously expensive.
Even worse, almost all Japanese SIM cards I tested had speed caps (2 Mbps, 10 Mbps, or “unrestricted” speed for the first few days before dropping). This includes 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 can recommend, but it is also expensive. In contrast, travel eSIM providers like Airalo offer a significantly cheaper alternative with better performance, even when roaming on local networks. This phenomenon is uncommon but can occur in countries where mobile operators throttle (prepaid) speeds.
Given that the Airalo Asialink eSIM is cheaper than any Japanese SIM card and performs significantly better, I highly recommend it if your phone supports eSIM.
Let's dive into the review and discover why I prefer eSIM over local Japanese SIMs!
Why Airalo eSIM Over Japanese SIM Cards
Stay Connected Wherever Without Breaking The Bank
In Japan, local SIM cards are notably expensive. During my stay, I spent approximately 50 030 JPY (around 360 USD) on Japanese SIM cards alone. In comparison, travel eSIMs from providers like Airalo are more affordable. For instance, the Airalo Asialink 100 GB eSIM costs 185 USD, while the Discover Global 20 GB eSIM is priced at 89 USD. Despite their lower cost, these eSIMs deliver superior performance.
Performance and Speed
One of the most significant drawbacks of Japanese SIM cards is the speed caps imposed on them. As I already mentioned, most cards offer speeds of 2 Mbps or 10 Mbps, with some providing “unrestricted” speeds for the first few days before throttling. These limitations apply even to SIM cards advertised without a FUP, promising speeds up to 788 Mbps. My tests revealed that, in practice, these speeds were rarely achieved.
If you opt however to go for a local Japanese SIM anyway, check out my review.
Where Can You Use The Airalo Asialink eSIM?
The Airalo Asialink eSIM can be used in 14 countries in Asia, predominantly in East and Southeast Asia, including Cambodia, China, Hong Kong, Indonesia, Japan, Laos, Macau, Malaysia, the Philippines, Singapore, South Korea, Taiwan, Thailand, and Vietnam.
This makes it a convenient and cost-effective option for travelers planning to visit multiple countries in these regions. Unlike its European counterpart, Eurolink (which I used in 11 countries), the Airalo Asialink eSIM does not yet support 5G NR, but this feature may be available in the future.
If you are traveling to Europe, check out my Eurolink guide.
My Airalo Asialink eSIM in Japan Experience
I used my Airalo Asialink eSIM in Hiroshima, the Kansai region (mostly Osaka, but also Kobe, Kyoto, and Nara), and Tokyo Metropolis (mostly Chiyoda City, but also Shinjuku City, Taito City, and Yokohama City).
Travel eSIM providers like Airalo set up roaming agreements with local operators because they cannot operate in every country.
This setup avoids exorbitant roaming costs. In Japan, the Airalo Asialink eSIM uses the SoftBank and AU by KDDI networks through Singtel from Singapore, so your phone may display Singtel as the network.
Network Performance and Selection
I primarily used the SoftBank network without actively tracking it. Manually selecting a network is unnecessary as SoftBank and AU by KDDI offer similar performance. Japanese operators do not focus on prepaid services, so I used Mobile Virtual Network Operators (MVNOs) like IIJmio, which uses the NTT Docomo network. These SIM cards were throttled to 2 Mbps or 10 Mbps or slowed down after a few days, unlike the travel eSIMs, including Airalo's Asialink eSIM, which were unaffected.
And testing nine travel eSIMs using the networks of NTT Docomo, SoftBank, and AU by KDDI yielded varying results. Japan's 4G/LTE availability is impressive, covering at least 99.4% of the country, making 3G fallback rare. While the Airalo Asialink eSIM did not support 5G NR during my visit, the speeds were still noteworthy.
Speed Test Results
- NTT Docomo: Median download speed of 48.86 Mbps
- SoftBank: Median download speed of 44.77 Mbps
- AU by KDDI: Median download speed of 41.60 Mbps
Upload speeds were led by SoftBank at 9.24 Mbps, followed by NTT Docomo at 6.97 Mbps and AU by KDDI at 6.40 Mbps. These results indicate roughly equivalent speeds among the three operators.
I conducted speed tests using the Speedtest app across three regions in Japan. Average download speeds of 25 Mbps and upload speeds of 10 Mbps are sufficient for most uses, including 4K streaming and social media live streaming. Ideally, download speeds should be 100 Mbps+ on 4G/LTE.
Airalo Asialink eSIM Speed Test Results in Hiroshima
Hiroshima is mainly known for the tragic events of 1945. However, today, its radiation levels are comparable to other Japanese cities.
Besides its historical significance, Hiroshima offers attractions like the Hiroshima Castle. It is worth visiting, either as a day trip or a weekend getaway from the Kansai region.
Despite its size, 5G NR was unavailable in Hiroshima. The technology was absent across the city, even though COMST Japan and Ubigi Japan, both using the NTT Docomo network, have 5G NR access. This created a level playing field for comparing Japanese SIM cards and travel eSIMs on 4G/LTE.
In Hiroshima, I tested the Airalo Asialink eSIM, achieving decent internet connection speeds. Though I only got results from seven test locations, it was enough to gauge performance. Results are indicated as follows: underlined for 5G NR, italicized for 3G, green for the fastest result, and red for the slowest at each location.
The Airalo Moshi Moshi and Nomad APAC eSIMs also used the SoftBank network, while the Nomad Japan eSIM used the NTT Docomo network. The Airalo eSIMs performed similarly well, with the Nomad APAC eSIM being notably slower.
The Airalo Asialink eSIM, powered by Singtel from Singapore, had an average download speed of 40.59 Mbps and a median download speed of 40.91 Mbps, passing the 4K video streaming test. The average upload speed was 11.26 Mbps, and the median was 8.09 Mbps, just meeting the requirements for HD live streaming.
At Mitaki Station, the Asialink eSIM reached a download speed of 124.52 Mbps, while the Moshi Moshi eSIM managed only 56.13 Mbps.
COMST Japan, using the NTT Docomo network directly, had slightly faster download speeds (average of 70.48 Mbps) but significantly slower upload speeds (average of 9.15 Mbps).
Airalo Asialink eSIM Speed Test Results in the Kansai Region (Kobe, Kyoto, Nara, and Osaka)
The Kansai region, Japan's second-largest after the Kanto region, includes Osaka, Kyoto, Kobe, and Nara. Most visitors stay in Osaka, but exploring the other cities is highly recommended due to their proximity and cultural significance.
During my trip, I found that most Japanese SIM cards are slow, even in Osaka, which is Japan's third-largest municipality and has 5G NR (used with COMST Japan and Ubigi Japan). Despite not being powered by a Japanese operator, the Airalo Asialink eSIM performed well in Kansai.
The eSIM provided an average download speed of 40.59 Mbps and a median of 40.91 Mbps, sufficient for 4K video streaming, with an average upload speed of 11.26 Mbps and a median of 8.09 Mbps, meeting HD live streaming requirements.
The fastest download speeds recorded were at Kitahama Station in Osaka (115.67 Mbps) and a bar in Osaka's Kita Ward (98.91 Mbps).
The Asialink eSIM was the fastest at nine other locations, including the Imperial Palace in Kyoto (83.93 Mbps), Imafuku-Tsurumi Station in Osaka (67.66 Mbps), and Imamiya Station in Osaka (62.36 Mbps). Average download speeds were 39.10 Mbps in Kobe, 47.97 Mbps in Kyoto, 37.32 Mbps in Nara, and 39.84 Mbps in Osaka.
While average upload speeds in Japan are relatively slow by East Asian standards, the Asialink eSIM had the fastest upload speeds at four locations, including Kansai International Airport Station (19.18 Mbps), Demachiyanagi Station (33.42 Mbps), and Nijō Castle (29.06 Mbps) in Kyoto, and Imafuku-Tsurumi Station (37.35 Mbps) in Osaka.
Overall, the Airalo Asialink eSIM provided reliable performance across the Kansai region, often outperforming other travel eSIMs and local MVNOs.
Airalo Asialink eSIM Speed Test Results in Tokyo Metropolis (Chiyoda, Shinjuku, Taito, and Yokohama)
Tokyo Metropolis, with its bustling cityscape and bright lights, consists of 26 cities, a few towns, and villages, totaling 39 municipalities. During my visit, I explored Chiyoda, Shinjuku, Taito, and Yokohama. The Airalo Asialink eSIM delivered decent speeds across Tokyo Metropolis.
Using the SoftBank network, the Airalo Asialink eSIM had an average download speed of 45.65 Mbps and a median download speed of 40.76 Mbps, passing the 4K video streaming test. The average upload speed was 10.25 Mbps, and the median was 7.44 Mbps, just meeting the HD live streaming requirements.
The fastest download speeds recorded with the Airalo Asialink eSIM were at Arcakit Kinshichō Mall in Sumida City (67.75 Mbps) and Mitsui Outlet Park Yokohama Bayside (39.33 Mbps). Additionally, I achieved download speeds faster than 100 Mbps at Gransta Mall in Chiyoda City (102.08 Mbps) and Narita International Airport Terminal 2-3 Station (121.12 Mbps).
While the eSIM had the slowest download speed at ten of the 31 locations, the speeds were within a reasonable range compared to the Airalo Moshi Moshi and Nomad APAC eSIMs.
The upload speeds were also comparable, with impressive speeds at Keisei Ueno Station (37.25 Mbps), Baskin Robbins near Yokohama Station (26.64 Mbps), and Mansei Bridge in Chiyoda City (21.26 Mbps).
With average upload speeds ranging from 8.68 Mbps to 10.88 Mbps, the Airalo Asialink eSIM performed similarly to the other eSIMs, making it a reliable choice for staying connected in Tokyo Metropolis.
So How Much Does it Cost to Get Your Hands on Airalo Asialink eSIM?
If you want to purchase Airalo Asiliank eSIM yourself these are the fees you should expect to pay.
- Asia/Asialink 1 GB eSIM for 7 days, costing 5 USD
- Asia/Asialink 3 GB eSIM for 30 days, costing 13 USD – very popular with Phone Travel Wiz readers
- Asia/Asialink 5 GB eSIM for 30 days, costing 20 USD – most popular with Phone Travel Wiz readers
- Asia/Asialink 10 GB eSIM for 30 days, costing 37 USD – very popular with Phone Travel Wiz readers
- Asia/Asialink 50 GB eSIM for 90 days, costing 100 USD
And if you need more data, you can always top up in just a few minutes with the 3 GB top-up (30 days costing 13 USD) or the 100 GB top-up (180 days costing 185 USD). And you can also use the Airalo app or the Airalo website to potentially find a better top-up option.
And if your credit/debit card charges you foreign exchange fees, get yourself a Wise Borderless Account and Debit Card.
My Overall Experience with the Airalo Asialink eSIM in Japan – Is It Any Good?
I highly recommend the Airalo Asialink eSIM for Japan, making it one of my top choices for anyone seeking an Asia travel eSIM. However, if you only plan to visit Japan, the Airalo Moshi Moshi eSIM might be a better option due to its cost efficiency.
Why Choose the Airalo Asialink eSIM?
The Airalo Asialink eSIM offers the advantage of being usable in over ten East and Southeast Asian countries, which can result in significant savings for travelers visiting multiple countries. For example, some countries like Laos offer only one eSIM variant (1 GB/7 days), making the Asialink eSIM more economical. Topping up with a data package option repeatedly in Laos would cost around 95 USD for 10 GB, compared to just 37 USD with the Asialink eSIM.
Easy Setup and Generous Data Usage Allowance
Setting up the Airalo Asialink eSIM is straightforward, and it offers the most generous data allowance among Asia eSIMs, with options ranging from 1 GB to 100 GB. In Japan, the eSIM uses the SoftBank and AU by KDDI networks, both of which provide excellent 4G/LTE coverage. I primarily used the SoftBank mobile network, but you can manually select AU by KDDI if needed.
Performance in Japan
The Airalo Asialink eSIM provided one of the fastest network experiences compared to other travel eSIMs I used in Japan. Among the local SIM cards, only COMST Japan was significantly faster due to its 5G NR access in the Kansai Region and Tokyo Metropolis. In 91 speed tests, the Airalo Asialink eSIM had an average download speed of 44.02 Mbps and a median download speed of 40.91 Mbps. The average upload speed was 11.28 Mbps, with a median of 9.89 Mbps.
Comparison with Local SIM Cards
The upload speeds are not impressive because Japanese mobile operators generally have slower upload speeds. While it would be ideal to compare the Airalo Asialink eSIM directly with SoftBank, obtaining a prepaid SoftBank SIM card was not feasible as only MVNOs sell prepaid SIM cards, and they throttle speeds aggressively. Therefore, no direct comparison with SoftBank was possible.
Among the tested SIM cards, only COMST Japan was faster. The Japan Wireless eSIM, using the AU by KDDI network through China Mobile Hong Kong, had an average download speed of 47.35 Mbps but was only tested in Tokyo Metropolis. The Airalo Moshi Moshi eSIM performed well, but the Airalo Discover Global eSIM was the slowest, with an average download speed of 10.05 Mbps in the Kansai region.
Wrap Up
So, with all of that in account, for travelers visiting multiple East and Southeast Asian countries, the Airalo Asialink eSIM is an excellent choice due to its cost-effectiveness and high performance. For those visiting only Japan, the Airalo Moshi Moshi eSIM is recommended.
By using a near-perfect 4G/LTE network, offering affordable data plans (cheaper than Japanese SIM cards), and providing super-fast download speeds, the Airalo Asialink eSIM ensures a smooth browsing experience.