When traveling in Japan, you will often have the opportunity to use subways, underground shopping areas, and underground stations. Therefore, some may wonder, "Can I use eSIM underground?" or "Will I lose connectivity when I go underground?"
To conclude, eSIMs for Japan can be used underground. In major cities in Japan, there are many places where mobile communication is available even in subways, station interiors, and underground shopping areas.
However, depending on the depth of the underground, the facilities, and the location, the communication speed may decrease, or it may become temporarily difficult to connect.
In this article, we will explain in detail the communication status of eSIMs underground, places where communication tends to be unstable, and points for comfortable use.
Can eSIM be used underground?
Yes. Since eSIMs use the same mobile communication network as physical SIMs, you can access the internet in places where communication facilities are available underground.
Google Maps, transit guides, social media, and messaging apps can usually be used as normal.
The quality of communication is determined not by the eSIM itself, but by the service provider you connect to and the condition of the underground facilities.
Examples of places where communication is possible underground
| Location | Communication Status Indicator |
|---|---|
| Subway station | 〇 Often available |
| Inside subway cars | 〇 Available in many sections |
| Underground shopping area | 〇 Relatively stable |
| Underground passage | 〇 Many places are available |
| Long underground tunnels | △ May become temporarily unstable |
In major cities such as Tokyo, Osaka, Nagoya, Fukuoka, and Sapporo, there are extensive areas where communication is possible underground.
Cases where communication tends to be unstable underground
Although there are many places where communication is possible underground, the following environments may lead to decreased communication speed or unstable connections.
- Platforms located deep underground
- Long tunnel sections
- Places with few underground facilities
- Peak times with high user concentration
- Underground facilities located deep within buildings
In many cases, communication will recover when you move to a different location or arrive at a station.
Apps commonly used underground
| Purpose | Examples |
|---|---|
| Route search | Google Maps, transit guide |
| Confirming station exits | Google Maps |
| Translation | Google Translate |
| Tourist information | Search engines, travel sites |
| Messaging | LINE, WhatsApp |
Since there are places underground where it can be difficult to determine direction, being able to use Google Maps or transit guides will help you move smoothly to your destination.
Points for comfortable communication underground
- Set up your eSIM before traveling
- Save Google Maps for offline use
- Save the addresses of your hotel and destination
- Choose a plan with ample data capacity
- Check mobile data settings as needed
Since communication conditions can change temporarily underground, it is reassuring to save necessary information in advance.
Points to note when using eSIM underground
While eSIMs can be used underground, to ensure more comfortable communication, check the following points.
- Communication speed may temporarily decrease in deep underground areas
- In long underground passages, signal conditions may vary by location
- It is reassuring to prepare offline maps for Google Maps
- Save the addresses of your hotel and destination in advance
- Select sufficient data capacity based on the number of travel days
In large underground areas such as Tokyo Station, Shinjuku Station, and Umeda Station, while many places are equipped with communication facilities, communication speed may decrease during peak times when many users are present. If you save necessary information in advance, you can feel secure even if communication becomes temporarily unstable.
Frequently Asked Questions
Can eSIM be used underground?
Yes. In places where communication facilities are available, such as subway stations and underground shopping areas, you can use the internet as usual with eSIM.
Will I lose connectivity when I go underground?
It does not necessarily mean that you will lose connectivity. The communication status varies depending on the underground facilities and locations, but there are many places where communication is possible in major cities in Japan.
Can I use Google Maps in underground shopping areas?
Yes. If communication is available, you can use Google Maps to check your current location, exits, and routes to your destination.
Is the communication status different between subways and underground shopping areas?
Both often have well-equipped communication facilities, but the communication status varies depending on the depth of the underground and the structure of the facilities. In some sections, communication speed may decrease.
Is free Wi-Fi enough underground?
While there may be free Wi-Fi available in underground shopping areas and station interiors, the locations where it is available are limited. If you want stable communication while moving, mobile communication such as eSIM is recommended.
How many GB do I need for underground use?
If you are only using maps or transit guides underground, 3 to 5 GB may be sufficient. If you frequently post on social media or watch videos, a plan with 10 GB or more or an unlimited plan is recommended.
Should I set up eSIM before traveling?
Yes. If you set it up before your trip, you can smoothly access the internet even after moving from the airport to the subway or underground shopping areas.
Summary
eSIMs for Japan can be used in many underground areas, such as subway stations, underground shopping areas, and underground passages. While there may be some instances of unstable communication, the communication environment is well-established in major cities, allowing for comfortable use during sightseeing and travel.
- eSIM can be used underground
- There are many places where communication is possible in subway stations and underground shopping areas
- Communication speed may decrease in deep underground areas or during peak times
- Utilizing offline storage for Google Maps is reassuring
- Select appropriate data capacity based on the number of travel days
By preparing your eSIM before your trip, you can smoothly check maps, transit guides, and tourist information even underground, making your travel in Japan more enjoyable.
