Before buying a used iPhone, verify the handover, test the hardware yourself, and record anything you could not check. A battery percentage or a seller’s screenshot cannot replace using the actual phone.
Device Status⁺ → Tools → Quick Check guides you through eight hardware checks and saves your observations. Use it during an in-person sale or when inspecting a delivered phone within the agreed return period.
What should you check before paying?
Agree with the seller that you can unlock the phone and open test tools. Bring a working charging cable and adapter, and arrange a suitable SIM or eSIM test. The seller should back up their data and handle account removal and erasure themselves.
- Activation Lock: do not buy a locked device. See Apple’s used iPhone guidance.
- Handover: complete online setup without the previous owner’s account. The Hello screen alone is insufficient. See Activation Lock.
- Repairs: check Parts and Service History in Settings → General → About; coverage varies by model.
- Carrier compatibility: inspect the carrier lock entry in About, following Apple’s carrier unlock guidance.
Compare the model and storage with the listing. Inspect the frame, lenses, connector and buttons. Missing repair records do not establish that a phone has never been opened; Device Status⁺ cannot complete ownership transfer for the seller.
Run eight hardware checks with Device Status⁺
Open Tools → Quick Check and start a session. Open each tool, perform the test, then return to record your finding and a note.
| Check | What to do | What to look for |
|---|---|---|
| Screen | Change colors and brightness in Color & Brightness | Persistent bright dots, dark spots, patches or image retention |
| Touch | Cover the Multitouch Grid Test and inspect Trails | Missed edges, gaps, jumps or touches without contact |
| Camera | Switch between available front and rear cameras; aim near and far | Persistent black preview, poor focus or abnormal blur |
| Microphone | Record a short phrase and play it back | Missing audio, crackling or interruptions |
| Speaker | Play Volume test audio at a comfortable level | Distortion, unexpectedly low output or silence |
| Vibration | Start the Vibration test | Whether you feel the expected response |
| Biometrics | Authenticate with an enrolled face or fingerprint | The actual Face ID or Touch ID result |
| Proximity | Cover and uncover as the Proximity tool instructs | Whether the detected state changes |
Disconnect Bluetooth headphones before audio tests. Check camera and microphone permissions if a tool cannot start. A missing lens is not a fault if that model never had it.
Quick Check results are manually confirmed observations. Skipped, unavailable and untested items are not passes. You can finish after recording every step, but a completed report does not mean every component passed.
How do you test touch and Face ID fairly?
Move slowly around all four screen edges before covering the grid. Repeat a missed area in another direction and note its location. Color tests reveal visible problems; they cannot establish that a display is original.
Before handover, have the seller authenticate with their enrolled face. After transfer, set up and test your own. An unenrolled buyer’s face, a cancelled prompt or a temporary biometric lockout is not evidence of broken hardware. This test checks an authentication attempt, not component provenance.
What battery health is acceptable on a used iPhone?
There is no single percentage that decides whether a phone is worth buying. Review the battery health page in Settings alongside service messages, observed behavior and the possible cost of replacement. A 100% reading does not establish that the whole phone is new or unrepaired.
If an analytics log is already available, Tools → Battery Log Analyzer can add supported capacity and cycle records. Follow the battery log guide. Missing fields are not zero, and no available log is not a battery failure.
Try charging with known-working accessories and observe connection stability. An in-app charging-power estimate is not a measurement of the charger’s output and should not decide whether the port is sound.
What else should you test outside Quick Check?
Make an ordinary call and listen through the earpiece. Try Wi-Fi and cellular data with the service you intend to use, connect a Bluetooth accessory, and operate physical buttons. Record and replay a video in the system Camera app.
For your own needs, open GPS, compass and motion tools under Hardware. Poor indoor positioning alone is not a hardware diagnosis. On an equipped model, the LiDAR tools also show depth and point clouds; models without LiDAR do not need to pass that test.
Save evidence you can actually use
Write a specific note such as “bottom-right touch grid missed twice,” then save the Quick Check session. Previous reports can be reopened and shared as text.
For a separate device-information snapshot, Tools → Export Report generates a system PDF. That PDF and the manually recorded Quick Check report serve different purposes. Review device and network information before sharing either.
Can an iPhone testing app guarantee original parts or no water damage?
No. Device Status⁺ helps you reproduce symptoms and avoid missed checks. It does not certify original parts or exclude internal liquid damage, hidden repairs or intermittent faults.
Repeat a suspicious result and discuss it with the seller. If the condition remains uncertain, get a professional inspection. Keep untested items visible and use your findings alongside the sale terms instead of treating a completed checklist as a guarantee.
Ready to try it?
Device Status⁺ · Monitor and test your iPhone hardware
Free on the App Store