Japan Portable WiFi: How to Make Comparison Shopping Easy

Are you comparison shopping for Japan Portable WiFi? Be careful with making your decision on the rental price alone. By understanding the fine print, you can have a better understanding of what you’re getting before you turn on your WiFi in Japan. Keep reading to find out the 4 important things to consider when shopping around.

Comparison Shopping for Japan Portable WiFi

While there are many Japan Portable WiFi options to choose from, we have chosen four popular models to explain what to look for when comparison shopping.




Pocket WiFi Model

Pocket WiFi 305zt Pocket WiFi GL06P WiFi Walker HWD11

Sakura Mobile Unlimited Pocket WiFi

Normal LTE Data Rate (Specification)

75 Mbps 75 Mbps 75-150 Mbps 75-150 Mbps

Maximum LTE Data Rate (Specification)

165 Mbps 165 Mbps 225 Mbps 300 Mbps

Real LTE Data Rate

10-35 Mbps (possibly up to 40 Mbps) 10-35 Mbps (possibly up to 40 Mbps) 10-30 Mbps 10-30 Mbps

Fair Usage Policy*

1 GB / 3 Days 1 GB / 3 Days 3 GB / 3 Days 300 MB-1.2 GB / Day (depending on plan)

Monthly Data Limit**

7 GB 10 GB au LTE = 7 GB UQ Wimax = None None

Network Coverage***

Y!mobile LTE Y!mobile LTE au LTE + UQ Wimax Docomo LTE

* Fair Usage Policy: The total amount of data you are allowed to use over a short period (usually measured in days). If you go over this limit, your data transfer speed is throttled (slowed down) until the limit is allowed to reset. ** Monthly Data Limit: The total amount of data you are allowed to use in one month. If you go over this limit, your data transfer speed is throttled (slowed down) until the next billing cycle. *** Network Coverage: Y!mobile is the smallest LTE network in Japan. au is considered the second most reliable LTE network in Japan; Wimax is a supplemental LTE network for au that offers weak coverage. Docomo is Japan’s largest LTE network.

4 Things to Consider When Comparing Japan Portable WiFi

  1. Real LTE Data Rate
  2. Fair Usage Policy
  3. Monthly Data
  4. Network Coverage

1. Real LTE Data Rate

It’s important to remember that the data transfer speeds listed by network carriers in the WiFi router specifications are for ideal situations. Because of this, it’s better to consider the real LTE data rate, which network carriers do not usually provide to customers. We were able to combine our industry experience with a collection of actual user reviews to come up with what we consider to be the real LTE data rates for each network carrier.




10-35 Mbps 10-30 Mbps 10-30 Mbps

What we found was that while all three carriers-Y!mobile, au, and Docomo can provide data rates of 10-30 Mbps in real speed, Y!mobile tends to have slightly better speeds, topping out at 35 Mbps. (While Y!mobile can slightly outperform competitors in terms of speed they have a significant drawback due to their limited coverage area.)

Can you get by with less than 10 Mbps?

Based on our research, we found that for visitors in Japan, a real data rate of 10 Mbps or higher is satisfactory for most people. Our Sakura Mobile Unlimited Pocket WiFi, which connects to Docomo’s LTE network, currently has a set target speed of 10-20 Mbps. You can go much deeper into other factors that affect data transfer speed, like pinging or photo and video compression; however for the comparison above, it isn’t really necessary. Tip: Be careful when considering low-speed WiFi models. They can work fine for light data use, like messaging apps, but you will likely notice slow data rates with even simple travel apps like Google Maps. Yes, these low-rate plans are cheap, but you get what you pay for.

2. Fair Usage Policy

The fair usage policy can be tricky to understand, and can become very stressful if you’re not careful with how you use your data. Basically, the fair usage policy manages the amount of data you can transfer (send and receive) over short period (usually measured in days). Once you have reached the data limit, throttling kicks in to slow down your data transfer speed. To show you how a fair usage policy calculates your data limit, let’s look at the Y!mobile 305zt and GL06P plans, which offer 1 GB of data over a 3-day period.

Day 1 Day 2 Day 3 Day 4 Day 5 3-Day Data Usage

Daily Transfer Limit (1 GB / 3 Days)

300 MB + 500 MB + 200 MB = 1 GB (1,000 MB)
500 MB + 200 MB + 300 MB = 1 GB (1,000 MB)
200 MB + 300 MB + 500 MB = 1 GB (1,000 MB)

If on Day 1 you use 300 MB of data and on Day 2 you use 500 MB of data, you only have 200 MB of data available on Day 3 before throttling kicks in. On Day 4, you have 300 MB of data before throttling kicks in because Day 1 is no longer counted as part of the fair usage policy data limit. While the fair usage policy information couldn’t be found for the au WiFi Walker HWD11, it can probably be assumed that the “3 GB / 3 Days” policy functions similar to the Y!Mobile plans. Also, from our past experience, in general, au WiFi tends to offer a bigger data allowance than the Y!mobile plans, so there is less chance of throttling when comparing the two.

How does Sakura Mobile Unlimited Pocket WiFi compare?

There are some major differences between what Y!mobile and au offer when compared with the Docomo Unlimited Pocket WiFi plans available from Sakura Mobile. We design our Pocket WiFi plans to provide much more flexibility for our customers.

  • We offer three data plans (Lite, Regular, Deluxe) that let you decide when throttling kicks in.
  • Your data limit resets at the end of each day so you don’t have to wait 2 or 3 days to get your high-speed Internet back.
  • If throttling kicks in, you can buy additional data with an easy top up so you always stay connected.
  • Unlike our competitors, we let you keep your unused data quota by carrying it forward.

All of this flexibility, which can only be found with Sakura Mobile, really means less WiFi stress for you during your trip to Japan. Tip: Portable WiFi plans that include a fair usage policy can be a problem if you aren’t careful with how you use your data. Without monitoring your data, you can accidentally use up all of your alotted data on Day 1, leaving you with throttled data for Days 2 and 3. This may be okay at home, but when traveling in a foreign country, 2 days without Internet can cause you a lot of unwanted stress.

3. Monthly Data Limit

For most visitors to Japan, a Portable WiFi’s monthly data limit probably isn’t a big concern; but if you plan to stay in Japan for a month or more, then please keep reading. (If not, skip to the next section on network coverage.) Your monthly data limit is another data transfer cap that comes along with the fair usage policy and is often given as a monthly limit of 7 GB or more. It’s important to understand that while the standard fair usage policy is only applied toward your high speed (LTE) data transfers (this is the data you use before your WiFi is throttled), the monthly data limit is applied toward all data you use during the month, including any data when your WiFi is throttled. Below is an example of just how quickly you can go through your monthly data limit. Y!mobile Pocket WiFi 305zt (7 GB monthly data limit; 1 GB / 3 Days)

Day 1 Day 2 Day 3 Day 4 Day 5 5-Day Data Usage
High Speed (LTE) Data 800 MB + 200 MB + + 700 MB + 300 MB = 2 GB (2,000 MB)
Throttled Data 400 MB + 600 MB + + 500 MB = 1.5 GB (1,500 MB)
Total 5-Day Data Usage 3.5 GB (3,500 MB)

As you can see, it can be very easy to go through your monthly data limit in 10-14 days. In order to have your data last for the full month, you are only allowed to use 230 MB a day (230 MB x 30 Days = 6.9 GB). At Sakura Mobile, we have had customers switch to our Pocket WiFi plans, because unlike our competitors we do not set monthly limits.

4. Network Coverage

So, let’s go over something a little more simple network coverage. There are four LTE companies in Japan that offer some form of data coverage for tourists.

  1. Docomo (45% market share)
  2. au (30% market share)
  3. SoftBank (25% market share)
  4. Y!mobile (3% market share)

Historically, Docomo has maintained its position of having the largest number of subscribers in Japan, while Y!mobile (at the bottom of the big four), was established only as a data network, making it less popular. While the biggest is not always the best, Docomo’s continued reputation in Japan suggests high satisfaction in its services. Currently, there is a clear divide between the four carriers with Docomo and au considered having greater coverage across Japan through cell phone towers and long-range radio signals. SoftBank and Y!mobile are still working to grow their coverage and are not yet able to compete with the top two carriers. As for comparing Docomo and au, apart from Docomo offering wider coverage across Japan, they also use more standardized technology in their 3G network. This difference is minor, but we think this makes Docomo’s 3G network a little faster and more stable than au’s 3G network. Docomo’s advantage becomes even clearer when you travel outside of Japan’s major metropolitan areas. If you plan to visit Japan’s countryside, including Hokkaido, Kyoto, Mt. Fuji, ski resorts, and onsen (to name a few), then you have a greater chance of connecting to WiFi in remote areas with a Portable WiFi using Docomo’s data network. (Read more about Docomo’s remote data coverage.)

Great Portable WiFi Is in the Fine Print

Comparison shopping for Japan Portable WiFi doesn’t have to be confusing. By understanding the real LTE data rate, fair usage policy, monthly data limit, and network coverage, you can be make a better choice that fits your travel needs. At Sakura Mobile, we make it our highest priority to offer products and services that are tailored to our customers. We hope you will consider us for your Portable WiFi needs during your next trip to Japan. Please visit our product pages to learn more about our Unlimited Pocket WiFi plans.

Sakuramobile SIM Card
Sakuramobile WiFi router