iPhone has no hidden test menu like Samsung, but iOS still reports a lot about the hardware: battery health, replaced parts, crash logs and signal. Apple Support can also run a remote diagnostic. Here is where to find each one.
Check battery health
- Open Settings › Battery › Battery Health (Battery Health & Charging on some versions).
- Check Maximum Capacity. 80% or higher is healthy; iPhone 15 and later also show the cycle count in Settings › General › About.
- A Service message or Unknown Part means the battery needs attention or isn’t genuine.
Check for replaced parts
- Open Settings › General › About.
- Look for Parts and Service History. It lists a replaced battery, display, camera or other part, and whether it’s genuine Apple.
- If the section isn’t there, no parts have been flagged.
Run Apple diagnostics
- Contact Apple Support through the Apple Support app or getsupport.apple.com.
- The advisor can send a diagnostic request to the iPhone. Accept it, and keep the iPhone connected to Wi-Fi while it runs.
- Apple shares the results with the advisor, who tells you if any hardware failed.
Look for crash logs
Open Settings › Privacy & Security › Analytics & Improvements › Analytics Data. Many files starting with panic-full mean the iPhone restarts by itself, which often points to a hardware fault.
Test the parts built-in tools miss
Manufacturer diagnostics check that hardware is connected, but they rarely test everything you use. The MxMob phone diagnostic runs in the browser and checks every touch zone, left and right speakers, each camera lens, GPS accuracy, real Wi-Fi speed and more, then gives you a shareable report. Buying used? Follow the used phone checklist.
Diagnostic guides for other brands
Frequently asked questions
Is there a secret diagnostic code for iPhone?
No. iPhones don’t have a hidden hardware test menu. *#06# shows the IMEI and *3001#12345#* opens Field Test Mode for signal details. For hardware checks, use Settings, Apple Support’s remote diagnostics, or the free MxMob browser test.
How can I test a used iPhone before buying?
Check battery health and Parts and Service History in Settings, make sure Find My is off and the Apple ID is signed out, check the IMEI, and run the full MxMob diagnostic in Safari to test the screen, touch, speakers, microphone, cameras and sensors.
Does the MxMob test work in Safari on iPhone?
Yes. Open mxmob.com/check in Safari. iPhone asks for camera, microphone and motion access once, and tests that Safari doesn’t allow, like NFC, switch to a quick guided check.