Comprehensive Guide to au KDDI SIM Cards and eSIMs for Tourists

Planning a trip to Japan and need reliable mobile connectivity? This guide covers everything about au KDDI SIM cards and eSIM options. From choosing the right plan to activating your service, we’ll provide a clear and concise breakdown tailored for tourists, ensuring you stay connected hassle-free during your travels.

1. Quick Facts about au KDDI

au by KDDI has a long history of connecting Japan through innovative communications. Formed in 2000 when KDD, IDO, and DDI joined, KDDI Corporation now provides popular mobile, internet, and home phone services under the au brand.

• au by KDDI is a Japanese mobile phone operator, the second-largest in the country with over 60 million subscribers.
• It is a brand marketed by KDDI, a telecommunications company providing fixed-line phone, internet, and TV services.
• au offers a variety of mobile phone plans, including data plans, voice plans, and combination plans.
• It is known for its high-speed data network and its wide range of handset choices.
• au also offers a variety of other services, such as music streaming, video streaming, and mobile payments.
• The Japanese government requires big operators like NTT Docomo, KDDI (au), and SoftBank to share their networks with smaller providers (MVNOs) to promote competition and give customers more choices. So an MVNO using KDDI’s network has the same wide coverage and speeds as KDDI itself such as: Povo, BIC SIM, J:COM Mobile, UQ Mobile.

2. Why au by KDDI When You’re Exploring Japan – Coverage and Speed

Whether you’re in major cities or remote towns, au aims to keep you connected with wide-ranging 4G coverage and fast LTE speeds across the country.

2.1. au by KDDI Coverage in Japan

According to an October 2024 Opensignal report:

• Coverage Experience: au KDDI demonstrated strong overall coverage, earning 8.1 points on a 10-point scale. Placed second among Japanese operators. Shows strong nationwide network presence. Behind NTT DoCoMo but ahead of SoftBank and Rakuten.
• 5G Coverage Experience: For 5G-specific coverage, au KDDI scored 3.1 points, ranking second among Japanese operators. While competitive, this indicates there’s still room for improvement in their 5G network expansion.
• Availability: KDDI’s network availability was exceptional at 99.6%, meaning users could connect to either 4G or 5G services almost all the time. This demonstrates the carrier’s reliable network infrastructure.
• 5G Availability: Users could connect to 5G networks 12.1% of the time, showing that while 5G service is significant, it’s still in the expansion phase. This metric suggests that users spend more time on 4G than 5G networks.

Strong 4G signals can be expected in major cities, towns, and rural areas, as well as along highways, bullet trains, and subways. Au provides excellent nationwide coverage for tourists, with occasional gaps in remote mountains.

2. au KDDI Speed

In terms of mobile data speed, OpenSignal’s 2024 testing found Au achieved an average 4G download speed of 44.53Mbps in Japan:

• Download Speed Experience (54.7Mbps): KDDI comes first place with reliable speeds that support everyday mobile activities. This positions KDDI as a top-tier player for download speeds.
• 5G Download Speed (155.1Mbps): Shows significant speed improvement over 4G. Second place just behind Rakuten. Demonstrates KDDI’s 5G network capabilities. Enables high-bandwidth applications like 4K streaming. While impressive, it falls short of Rakuten’s leading 5G speeds (176.5 Mbps) but outperforms NTT Docomo (147.3 Mbps)
• Upload Speed Experience (8.5 Mbps): Sufficient for most common upload tasks. Supports stable video calls and social media uploads. It follows Rakuten Mobile (17.2 Mbps) and is slightly behind SoftBank (8.6 Mbps), making it a solid performer for uploads.
• 5G Upload Speed (17.5 Mbps): More than doubles the standard upload speeds. Enables faster sharing of high-resolution content. Trailing Rakuten Mobile (27 Mbps), KDDI maintains a competitive edge with SoftBank (19.4 Mbps).

KDDI au not only delivers strong 4G and 5G speed performance but also excels in other areas, earning awards for Video Experience, Games Experience, Live Streaming Experience, and Voice App Experience. These accolades highlight its ability to provide high-quality, seamless experiences across various applications, from streaming and gaming to voice communication.

3. au by KDDI Connectivity Options for Travelers to Japan

KDDI offers travelers to Japan various options for staying connected while abroad – physical SIM, eSIM, and roaming. The Pocket Wi-Fi service was discontinued in 2020.

The following table provides an overview of the key pros and cons of each option to consider when deciding what best fits your connectivity needs:

4. Best au Japan SIM Cards for Tourists & Cost

Starting in November 2018, au KDDI stopped accepting new prepaid phone signups in Japan. If your prepaid card expires, you cannot renew. Luckily, MVNOs offer prepaid alternatives on KDDI’s network for short-term visitors without contracts.

If you want to use the KDDI network, you can use the following Nippon SIM type:

KDDI Plans

5. Does au KDDI Support eSIM in Japan?

No, AU does not offer eSIM plans for travelers, only for residents. An eSIM allows mobile data activation directly on compatible phones without a plastic SIM.

If you’re looking for a different choice using the au mobile network, esimjapan.net also provides some fairly convenient travel eSIM options you could consider.

6. Where Can You Buy an au Japan SIM Card and eSIM?

Whether you’re traveling to Japan for work or pleasure, being able to connect to WiFi on the go is essential. Learn where you can buy an au Japan SIM card or eSIM.

6.1. Where to Buy au Japan SIM Cards

You can purchase au Japan SIM cards at:

• au Stores: au retail shops are found in most cities and airports. Find your closest AU store location using the store locator search tool.
• Convenience stores such as Bic Camera, Yodobashi Camera, and Yamada Denki frequently sell au SIM cards at airports and in city locations.
• For Nippon SIM: You can choose to pick up your SIM card at the airport or at the post office located in major Japanese airports. Please check the list of pickup locations to find detailed information for each airport. It’s recommended to use a translation app for assistance, as the link is only available in Japanese.

When buying in person, you may need your passport to register the SIM card. Online purchases will be shipped to your hotel or pick-up location.

6.2. Where to Buy au by KDDI eSIM in Japan?

Here are some options for buying an AU by KDDI eSIM in Japan:

• Bic Camera/Yodobashi Camera electronics stores: Major consumer electronics chains Bic Camera and Yodobashi Camera sell au eSIM packages in their stores. Staff can assist with activation.
• Supermarkets/convenience stores: AU partners with larger supermarkets like Aeon and convenience stores like Lawson to sell eSIM starter packs. Look in the telecom sections.
• eSIM providers: Small phone shops and online eSIM providers such as esimjapan.net carry eSIM packages with KDDI network. Activation support varies.

Ditch the hassle of physical SIM cards and enjoy instant connectivity in Japan with eSIM from esimjapan.net. Activate your plan before you land, save up to 70% on roaming fees, and enjoy seamless 4G LTE coverage across the country.

With flexible plans ranging from 3 to 30 days, eSIMs are perfect for any trip—whether you’re exploring Tokyo or relaxing in Kyoto. No waiting, no stress, and no plastic waste! Plus, setup is as easy as scanning a QR code, and 24/7 support is just a message away.

Upgrade your travel experience today at esimjapan.net and stay connected hassle-free!

7. How to Activate au Japan SIM Card/eSIM in Japan?

7.1. How to Use au by KDDI SIM Card in Japan?

All SIM cards usually come packaged with detailed instructions for activation. Here are the simple steps to activate your new AU prepaid SIM card:

1. Purchase the SIM card package from any AU store. It will have an activation code.
2. Insert the SIM into your unlocked phone and turn it on.
3. Activate by dialing *149# and following the voice prompts. You can choose your language here.
4. When asked, enter the long activation code from the package. Press to confirm.
5. You’ll hear your new balance and use time. Congrats, your SIM is now ready to use!

7.2. How to Activate au by KDDI eSIM?

Getting your KDDI eSIM set up for travel in Japan is simple with these steps:

• Purchase the perfect KDDI eSIM plan from esimjapan.net based on your trip length in the land of the rising sun.
• Download the eSIM profile to your device the day before your Japan adventure begins. That way you’ll be all set to go once you touch down.
• With a strong wifi connection, download the eSIM profile so you can access the internet during setup.
• Open the email from esimjapan.net and copy over the all-important activation info like ICCID and code.
• Insert the eSIM using the QR scan or manual entry of those ID numbers.

Follow the on-screen prompts to activate it with a quick setup process and you’re now free to roam around Japan without any physical SIM switching headaches. If questions come up, the esimjapan.net support squad is there to help you out.

8. au by KDDI Japan Call and SMS Rates

Even prepaid SIM cards include unlimited domestic calling and texting. International calls and texts will be charged separately:

So you can stay in touch with contacts in Japan without worrying about call or text charges. Just budget separately if planning international usage.

9. Useful USSD Codes for au KDDI SIM/eSIM

You can check your AU SIM card balance and info by dialing these shortcodes:

These shortcodes provide an easy way to quickly pull up your account status and balances when needed.

10. How to Top-up au KDDI SIM/eSIM

There are several ways to top up your au KDDI prepaid SIM card depending on your location and preference:

• au Shops: Visit any au shop and tell the staff you want to top up your prepaid SIM card. You can pay with cash, credit card, or au PAY.
• Convenience Stores: Most convenience stores in Japan, such as FamilyMart, Lawson, and 7-Eleven, offer top-up services for AU prepaid SIM cards. You can usually purchase top-up vouchers with different denominations and use them to top up your SIM card online or through the My au app.
• ATM Machines: Select ATMs, particularly those of au partner banks like Mitsubishi UFJ Bank and Bank of Yokohama, allow you to top up your au prepaid SIM card directly.
• Online: You can top up your au prepaid SIM card online through the My au website or app. You can pay with a credit card or au PAY.

11. FAQs about au KDDI Mobile in Japan

12. Final Words

In summary, au KDDI offers reliable connections for travelers in Japan. KDDI provides widespread coverage and fast speeds at affordable prices. An eSIM plan is very convenient if your device supports it. Otherwise, AU’s physical SIM cards are easy to purchase and activate. With their services, you can stay connected across Japan with a suitable solution from au.