How to Check Data Usage When Using eSIM in Japan

eSIM is extremely useful for both short-term stays and long-term travel in Japan. However, if you purchase a plan with limited data, you may experience speed restrictions if you do not manage your data usage properly. This is especially true if you frequently watch videos or use map applications, as they can consume a large amount of data without you realizing it.

In this article, we will introduce methods for checking data usage when using an eSIM in Japan and recommend useful data management apps. By using these methods, you can efficiently manage your data and maintain a smooth internet experience.

How to Check eSIM Data Usage

When using an eSIM in Japan, you may wonder how much data you have used and how much is left. You can check your data usage using the following methods:

For CDJapan eSIM Users

If you purchased an eSIM from CDJapan Rental, you can check your real-time data usage by logging into My Page.
My Page

Checking via Smartphone Settings

Smartphones have a built-in function to check mobile data usage. By using this, you can monitor your eSIM data consumption in real time.

For iPhone Users

iPhones display cumulative data usage unless manually reset. To track usage within a specific period, you need to reset the statistics manually.

For Android Users

Android devices allow automatic data reset at regular intervals, making it easier to track monthly data usage.

Data Usage Management Apps

If you want to monitor your data usage in detail and save data, using a dedicated data management app can be helpful.

My Data Manager (iOS / Android)

Automatically records data usage and allows you to set alerts.
Provides detailed data usage breakdown by app

GlassWire (Android)

• Visualizes data usage through graphs and enables real-time monitoring
• Includes a feature to block unnecessary background data
• Separates Wi-Fi and mobile data tracking

Data Usage (iOS)

• Simple interface for quickly checking data usage
• Sends notifications when the set data limit is reached
• Widget feature allows easy tracking from the home screen

Ways to Reduce Data Usage

If you have purchased an eSIM plan with a limited data allowance and notice your remaining data decreasing, you may need to take measures to conserve data for essential use. Here are some tips to reduce data consumption:

• Use Wi-Fi whenever possible (hotels, cafes, airports, etc.)
• Turn off autoplay for videos (YouTube, social media, etc.)
• Use Google Maps' offline mode (download maps in advance)
• Disable automatic loading of images and videos on social media

When you have limited data, try to minimize mobile data usage as much as possible to avoid running out of data.