You bought a daily or total-data eSIM for your trip, and all you’ve done is check Google Maps, send a few LINE messages and scroll Instagram now and then. So how did more than half your data just vanish?
Plenty of travelers have been there.
“Hey! I barely watched any videos, so how did I burn through 1GB already today?”
Often it’s not that you actually used that much. Some features on your phone may be quietly eating data in the background!
Automatic photo backups, app updates, background syncing, even connecting to weak Wi-Fi can all make your phone dip into mobile data without you noticing.
If your travel eSIM gives you 1GB or 2GB a day, or 5GB or 10GB in total, I really recommend checking these 8 settings before you fly.
In this post I’ll walk you through each one step by step. Whether you’re on iPhone or Android, it’s easy to follow!
1. Turn On Low Data Mode to Stop Your Phone From Sneaking Data
This is the first setting I recommend changing!
On iPhone
- Open “Settings”
- Tap “Cellular”
- Select your travel eSIM or “Cellular Data Options”
- Find “Data Mode”
- Choose “Low Data Mode”
Once it’s on, your iPhone cuts back on background network activity, automatic updates, some downloads and cloud syncing.
If you’re using dual SIM, double-check that you’re changing the setting for your travel eSIM.
On Android
Using a Google Pixel as an example:
- Open “Settings”
- Select “Network & internet”
- Tap “Data Saver”
- Turn it on
On Samsung phones, you’ll usually find it under “Settings → Connections → Data usage → Data saver”.
Quick reminder: Turning on a data saver doesn’t mean your phone will stop using background data completely, but it does cut down on unnecessary usage.
2. Turn Off Background App Refresh and Let Unused Apps Rest
Ever noticed that some apps keep updating content even when you haven’t opened them?
Social media, email and cloud services can all be transferring data in the background.
On iPhone
“Settings → General → Background App Refresh”
I suggest choosing “Wi-Fi”, or turning off Background App Refresh for apps you don’t need.
On Android
Go to “Settings → Apps”, pick a specific app, and look for settings related to “Mobile data” or “Background data”.
Menu names can vary a bit from brand to brand.
That said, I don’t recommend restricting LINE or important work messaging apps, since some messages or notifications may be delayed.
Restricting the apps you rarely use is more practical than shutting everything off!
3. Turn Off Automatic Photo Backup: This Could Be Where Your Data Is Going
Taking photos is one of the best parts of traveling!
But did you know?
If you have iCloud Photos or Google Photos auto backup turned on, your photos and videos may start uploading in the background right after you take them.
And since shooting 4K video on a phone is so common now, just a few clips can take up a lot of storage and upload data.
On iPhone
If you use iCloud Photos, I suggest turning on “Low Data Mode” for your travel eSIM so the system pauses some photo syncing.
You can also go to “Settings → [your name] → iCloud → Photos” to check your sync settings and status.
On Android
If you use Google Photos, you can:
- Open Google Photos
- Tap your profile picture in the top-right corner
- Go to “Photos settings → Backup”
- Find “Mobile data usage”
- Limit backups over mobile data, or turn off backing up videos over mobile data
My tip: Keep your photos on your phone while you’re abroad, then back them up once you’re at the hotel on Wi-Fi you trust.
But if you have important work photos on your phone, weigh the risk of delaying the backup. Don’t let saving data make you forget to save important files.
4. Turn Off Automatic App Updates and Save Them for the Hotel
A lot of people overlook this one!
Sometimes your phone downloads app updates automatically, and a few large apps together can use up quite a bit of data.
On iPhone
“Settings → Apps → App Store”
Check “App Updates”, “App Downloads” and the cellular data options.
I suggest avoiding automatic downloads or updates over cellular data for now.
On Android
- Open the Google Play Store
- Tap your profile picture in the top-right corner
- Go to “Settings → Network preferences”
- Tap “Auto-update apps”
- Choose “Over Wi-Fi only”
This lowers the chance of your phone downloading big updates automatically while you’re on the road.
Security updates are still important, so install any necessary updates once you have stable Wi-Fi.
5. Restrict Mobile Data for Specific Apps: Start With the Biggest Data Hogs
Some travelers keep Google Maps, LINE and Instagram open the whole trip, and that’s totally normal.
But if your phone also has games, streaming platforms or cloud drives you only use at home, there’s no need to let every app freely use your travel data.
On iPhone
“Settings → Cellular”
Scroll down and you’ll see each app’s cellular data usage along with an on/off switch.
You can turn off cellular data access for apps you won’t need on your trip.
That way, when you’re not connected to Wi-Fi, those apps won’t go online over cellular data.
On Android
In “Settings → Apps”, select an individual app to see its data usage and background data restrictions.
Some Android phones also offer more options for restricting mobile network access per app.
The key is to keep the apps you really need, not to turn off all network access in one go.
6. Lower the Quality on YouTube and Short Videos: It Makes a Huge Difference
Personally, I think this is the one people overlook the most.
Lots of travelers like to watch YouTube or scroll Reels or Shorts on the train, and once they start, they can’t stop.
Especially on YouTube, watching in 1080p or 4K can use a lot more data than standard quality.
On YouTube
- Open YouTube
- Tap your profile picture and “Settings”
- Find “Video quality preferences”
- Set mobile networks to “Data saver”
You can also manually pick a lower resolution while watching.
For Instagram and other social apps, check whether they offer settings for media quality, mobile data saving or video preloading.
If you’re just passing time on the train, you don’t really need the highest quality.
Save high-quality videos for when you’re on Wi-Fi. It helps a lot with a daily eSIM!
7. Turn Off Wi-Fi Assist So Your eSIM Data Isn’t Used When Wi-Fi Gets Spotty
This is another feature iPhone users should keep an eye on.
Say you’re using the hotel Wi-Fi and the signal suddenly drops.
Your iPhone’s “Wi-Fi Assist” may automatically switch to cellular data to keep you connected.
It’s convenient, but if you’re on a limited data plan, you may end up using your eSIM data without realizing it.
On iPhone
- Open “Settings → Cellular”
- Scroll down to “Wi-Fi Assist”
- Turn it off if you need to
If you’re keeping your Taiwan number active alongside your travel eSIM, I also suggest going to “Cellular → Cellular Data” to make sure your travel eSIM is selected, and checking whether “Allow Cellular Data Switching” is turned on.
This reduces the chance of cellular data switching to the line you didn’t intend to use.
Keep in mind, though, that with Wi-Fi Assist off, you may have to switch networks manually when Wi-Fi is unstable.
8. Monitor Your Data Usage to Find Out Which App Is Sneaking Data
Finally, here’s the habit I recommend most:
Every night when you get back to the hotel, check how much data you used that day.
How to Check on iPhone
Go to “Settings → Cellular”.
You can see how much data each app has used, and you can manually reset the statistics at the start of your trip to track usage over the whole journey.
How to Check on Android
Using a Pixel as an example:
“Settings → Network & internet → Internet → carrier settings → App data usage”
Some Android phones also let you set a data warning.
For example, if you bought a 10GB total-data plan, you can set the warning at 8GB to remind yourself to watch your remaining data.
Just note that your phone’s stats are usually for reference only. Your actual remaining balance is based on how your eSIM provider counts usage.
Bonus Tip: Download Offline Maps Before You Go!
Google Maps navigation usually isn’t the biggest data user, but downloading offline maps ahead of time is still really handy!
Using Google Maps as an example:
“Google Maps → profile picture → Offline maps → Select your own map”
Before you leave, download maps of the areas you’re visiting, like Tokyo, Osaka or Seoul, over Wi-Fi.
That way, even if you lose your connection for a while, you can still use some offline map features.
However, offline maps don’t necessarily support every feature, such as real-time traffic and public transit routes, and some countries or regions may not allow downloads.
I still recommend keeping some data in reserve so you can check transit info in real time.
Daily vs. Total-Data eSIM: Is There a Difference in How You Save Data?
Actually, there’s a bit of a difference!
| Plan Type | My Suggestion |
|---|---|
| 1GB per day | Turn off cloud backups, app updates and high-quality streaming first |
| 2GB per day | More flexibility for everyday navigation and social media, but still watch out for videos |
| 5GB total | Check your data every night and adjust usage based on how many travel days are left |
| 10GB total | Set a usage warning so you don’t burn through most of your data in the first few days |
A daily eSIM usually resets your daily high-speed allowance according to the plan’s rules, while a total-data eSIM shares one allowance across your whole trip.
So with a total-data plan, I especially recommend dividing your remaining GB by the number of travel days left and using that as your daily budget.
For example, if you have 6GB left and three days of travel to go, aim for about 2GB a day. (Not sure how much you use in a day? Check out our guide to calculating how much data you need for a Japan trip.)
FAQ
If I turn on Low Data Mode on my iPhone, will LINE still work normally?
Generally you can still send messages, make calls and get online, but some background updates and syncing may be limited. If you’re expecting important notifications, open the app yourself to check.
Is 1GB a day really enough for traveling abroad?
If you mainly use map navigation, LINE and restaurant searches, and cut back on data hogs like high-quality videos and background backups, some travelers can stay within 1GB a day. But there’s no guarantee it’ll be enough for everyone.
Should I turn off data roaming on my eSIM to save data?
Not necessarily, and don’t just switch it off!
Some travel eSIMs need data roaming turned on to connect properly.
Set up your travel eSIM according to the installation instructions for the plan you bought, and keep an eye on the roaming settings for your Taiwan number to avoid unnecessary international roaming charges.
Saving Data Doesn’t Mean Using Your Phone Less. It Means Not Letting Data Go to Waste!
Traveling abroad is meant to be enjoyed. You shouldn’t have to tiptoe around checking maps or sending photos just to save data.
I think the best approach is to get your phone set up before you leave!
Turn on Low Data Mode, restrict background usage, switch off automatic backups and updates, and check your remaining data every day. That way you can manage your daily or total-data eSIM much more effectively.
Save your data for when you really need it, instead of letting your phone quietly use it up in the background.
If you’re still not sure whether a daily, total-data or unlimited plan suits you best, head to the JEKO eSIM website and compare plans based on your trip length and usage habits. (You can also read 7 key tips for choosing a travel eSIM.)
Visit the JEKO eSIM website to find the right travel data plan for you
Wishing every traveler a happy trip and an easy connection!
