How much data messaging apps really use
Plain text costs almost nothing. What costs is the photos and videos the app downloads for you without asking — especially in a group that talks all day.
早わかり
- Plain text chat uses roughly 1–5 MB a day — small enough that you can leave it out of your planning entirely.
- A voice call over the app runs roughly 0.3–0.5 MB a minute; a video call jumps to roughly 5–9 MB a minute.
- Turning off automatic downloads of photos and video on mobile data is the one thing worth doing before you fly.
| What you are doing | Roughly how much | A 7-day trip at this rate |
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よくある質問
How much should I set aside for text chat alone?+
Almost nothing. Roughly 50 MB covers a seven-day trip even if you type all day. If contact with home is your main worry, the smallest plan is enough — everything else on the phone is what needs planning.
Is calling through LINE cheaper than a normal phone call?+
In data terms, calling through the app costs roughly 0.3–0.5 MB a minute from your plan. A conventional call from abroad is billed by whichever operator you are using under their own terms, which is a different system entirely and not one we can state figures for — check with them directly.
Will I miss anything if I turn off auto-download?+
No. Messages still arrive and the pictures are still in the chat, just as a blurred placeholder waiting for a tap. The one caution is that very old files can expire from the server after a long time, so tap to download anything important when you first see it.
Why do messaging apps use data when I am not in them?+
Because they have to receive incoming messages and may pre-fetch media that arrives. The volume is tens of megabytes a day at most. To cut it further, switch off Background App Refresh on iOS or Background data on Android, accepting that messages may land a little later.
Instagram and TikTok have no web share button, so we open your phone's share sheet or copy the link instead.