Usage history
iOS keeps its own records of which apps ran on the device and which resources they used. Usage history reads these records, so it can answer questions about past events that no live capture recorded.
What it contains
Section titled “What it contains”For each app session:
- Start and end time
- Duration
- Hardware used, such as CPU, GPU, display, radios, location and sensors
- Energy attributed to the app
Records go back up to six months, depending on how much data the device has kept. Older records are less detailed; recent weeks are complete.
Common uses
Section titled “Common uses”Investigating overnight battery drain. No capture was running overnight. Usage history shows which apps woke up, when, and for how long.
Finding background activity. An app that runs for four seconds every fifteen minutes does not stand out in a live capture, but adds up over a day.
Verifying a fix. Compare the two weeks before and after a release, for the same app on the same device.
Setting a baseline. Before optimizing, find out what normal usage looks like for this device and user.
Interpreting the data
Section titled “Interpreting the data”- Duration is not cost. A media app open for two hours can use less energy than a location-heavy app running for twenty minutes.
- Attribution is per process. Work your app triggers in a system service is attributed to that service.
- Usage varies by day. A difference between a heavy and a light day is usually caused by the user, not the code. Compare similar periods.
- Records are stored on the device. Resetting or restoring the device deletes them.
- Connect the device that the complaint came from, not a similar one.
- Open Usage history and set the time range to cover the reported period.
- Sort by energy. Check the apps above yours as well as your own. The cause is often a different app.
- For your app, open the sessions around the reported time and check which hardware was in use.
- Export the time range and attach it to the ticket.
Privacy
Section titled “Privacy”These records show how a person used their device. If the device belongs to a tester or customer, explain what you are reviewing and why, export only the time range you need, and delete the export when the ticket is closed. See the user agreement on authorized use.
Free and VIP features
Section titled “Free and VIP features”Usage history is part of the data analysis module, which requires VIP. See pricing.
Next steps
Section titled “Next steps”Energy and battery · Performance monitoring · App management