Does the iPhone warn you when you're running out of data?

No. iOS doesn't know your plan size, so it can't. You need an app like Databit, which compares measured usage against your plan and notifies you in time.

When does Databit alert me?

When your remaining data drops below 20%, again below 10%, and one final notification when it's exhausted.

Data usage alert on iPhone: how to set one up

Updated July 2026 · 3 min read · By the Databit team

The iPhone has no native data usage alerts: iOS doesn't know your plan size or billing date. With Databit you set your plan once and get automatic notifications when your data drops below 20% and 10%, plus a final one when it runs out.

The most expensive silence in iOS

Your iPhone notifies you about everything — except the one thing that costs you money every month. iOS doesn't know if your plan is 3, 5 or 50 GB, or when it renews, so it can't warn you as you approach the cap. You find out when the internet “gets slow”… or when the bill arrives with overage charges.

Set up your alerts in 2 minutes

Download Databit and open settings.
Enter your period data (your plan's GB) and your reset day — same as your billing day.
Toggle on Usage alerts. Done.

Databit settings screen with the Usage alerts option: notifications below 20% and 10% and when data runs out — One switch: notifications at 20%, 10%, and empty

How the three alerts work

20% left — the maneuvering alert. You still have margin: lower streaming quality, enable Low Data Mode, and coast to your reset date without paying extra.
10% left — the serious one. Survival mode: messaging and maps only, no video over cellular.
Data exhausted. Decide with a cool head: top up, or ride out the throttle until reset? Your call — not the fine print's.

Alerts that understand your billing cycle

The magic is the automatic reset: Databit restarts the count on your billing day, every cycle, so alerts are always computed against your current plan — not against a counter someone forgot to reset. Works with monthly, weekly or prepaid plans on any carrier.

Track your data usage in real time

Databit shows how many GB you have left, alerts you at 20% and 10%, and resets automatically on your billing day. One-time purchase, no subscription.

Get Databit — 4.6★ on the App Store