While using eSIM during my trip to Japan, I sometimes feel that the "connection speed is slow," "web pages take a long time to load," and "videos are buffering."
The reasons for slow eSIM connection speeds are not solely due to the eSIM itself. Various factors can be considered, such as signal strength, location, network congestion, data usage, and smartphone settings.
In this article, I will clearly explain the possible causes of slow eSIM connection speeds in Japan and provide easy-to-try solutions.
Main Causes of Slow eSIM Connection Speeds
| Cause | Check Points |
|---|---|
| Weak signal | Check if you are in a basement, inside a building, or in mountainous areas |
| Network congestion | Check if you are in crowded places like stations, event venues, or busy streets |
| Exhausted high-speed data allowance | Check your plan usage and speed limitation conditions |
| Unstable 4G/5G signal | Check network settings and your current location |
| Temporary issues on the smartphone side | Try airplane mode or restart the device |
| Excessive background data usage | Check for photo syncing, app updates, etc. |
If the connection speed is slow, do not jump to conclusions about the cause; check the easily verifiable items in order.
First, Move to a Different Location to Check the Connection
In basements, deep inside buildings, elevators, or mountainous areas, the signal may weaken, causing a drop in connection speed.
First, try moving to an outdoor area or near a window where the signal is easier to receive.
- Move from underground to above ground
- Move from deep inside the building to near a window
- Move from inside the station to outdoors
- Wait a moment and try reconnecting
If changing locations improves the connection speed, it is likely that the signal environment of that location was affecting the speed, rather than the device or eSIM.
Connection Speeds May Slow Down in Crowded Places
When many people use mobile data at the same time, the network can become congested, temporarily reducing connection speeds.
Particularly in the following places, you may be affected by congestion:
- Major train stations
- Airports
- Busy shopping districts
- Theme parks
- Concert and event venues
- Large tourist attractions
If congestion is the cause, moving to a different location or waiting a while before reconnecting may improve the situation.
Check if You Have Exhausted Your High-Speed Data Allowance
Depending on your eSIM plan, once you use a certain amount of high-speed data, your connection speed may be limited afterward.
For example, if you frequently watch videos, use social media, or tether, you may consume your data allowance faster than expected.
- Check your remaining data allowance
- Check the high-speed data usage limit
- Check the conditions for speed limitations
- Check if you can purchase additional data
Even plans labeled "unlimited" may have speed controls under fair usage policies. Be sure to check the conditions of the eSIM product you purchased.
Check 5G/4G Connection Settings
In areas with weak 5G signals, switching between 5G and 4G may cause unstable connections.
Also, just because 5G is displayed does not guarantee it will be faster than 4G. Actual connection speeds can vary based on signal strength and network congestion.
If the connection is unstable, check your device's mobile data settings. The settings may differ between iPhone and Android, as well as by manufacturer.
Try Turning Airplane Mode On and Off
If the network connection is temporarily unstable, turning on airplane mode and then turning it off may help reconnect to the network.
- Turn on airplane mode
- Wait a few seconds
- Turn off airplane mode
- Wait until mobile data reconnects
- Check the connection speed
Restart Your Smartphone
If switching airplane mode does not improve the situation, try restarting your smartphone.
Restarting may reload the connection settings and resolve temporary connection issues.
Check Background Data Usage
If cloud syncing of photos or app updates are running in the background, they may consume bandwidth and data allowance, leading to a perceived decrease in speed.
- Check for cloud syncing of photos and videos
- Stop automatic app updates
- Stop unnecessary downloads
- Turn off automatic video playback
- End unnecessary tethering
Stopping unnecessary high-volume data usage while traveling can also help save on data costs.
Do Not Delete the eSIM Just Because the Speed is Slow
It is not advisable to delete the eSIM just because the connection speed is slow.
Depending on the eSIM, you may not be able to reinstall it using the same QR code after deletion. First, check the coverage area, data allowance, and device settings.
If the situation does not improve after a long time, contact the support of the eSIM service you are using.
Frequently Asked Questions
Is slow eSIM connection speed a sign of malfunction?
It is not necessarily a sign of malfunction. Connection speeds can vary based on signal strength, network congestion, location, data allowance, and device settings. First, check your location and settings.
Can 5G connection speeds be slow?
Yes. Even with a 5G display, if the signal is weak or if you are in a crowded area, you may not achieve the expected speeds. It is important to check the actual connection status, not just the 5G display.
Is 4G/LTE sufficient for traveling in Japan?
Yes. For general travel purposes such as Google Maps, LINE, web searches, and social media, 4G/LTE is often sufficient.
What should I check if the connection speed suddenly drops?
First, check if you have exhausted your high-speed data allowance. Additionally, checking the signal strength and congestion in your current location, as well as background data usage, can help identify the cause.
Can eSIM be slow in basements or stations?
Yes. In basements, inside stations, or deep inside buildings, the signal may weaken, leading to a drop in connection speed. Moving to above ground or outdoors may improve the situation.
Does toggling airplane mode help improve the connection?
If there is a temporary network connection issue, toggling airplane mode on and off may help reconnect to the network and improve the situation.
Should I reinstall the eSIM when the connection speed is slow?
It is not advisable to reinstall immediately. Depending on the eSIM, you may not be able to reinstall it after deletion. First, check the coverage area, data allowance, and device settings.
What should I do if nothing seems to help with the slow speed?
If the situation does not improve after a long time, contact the support of the eSIM service you are using. Providing details about your location, device name, connection status, and times when the speed drops can help expedite the process.
Conclusion
Even if the eSIM connection speed is slow in Japan, it does not necessarily mean there is a problem with the eSIM itself. Various factors such as signal strength, congestion, data allowance, and device settings can be considered.
- Move to an area with better signal
- Avoid crowded places and times
- Check your remaining high-speed data allowance
- Check your 5G/4G connection settings
- Try toggling airplane mode or restarting your device
- Reduce background data usage
- If the situation does not improve, contact your service provider
During your trip to Japan, it is important not only to check the speed display but also to ensure that essential services like Google Maps and transit guides are functioning smoothly. If the connection is slow, check each potential cause one by one to improve the situation.
