Start with how you use your phone
Think about what you want to improve. A larger screen can make reading and watching video more comfortable, while a smaller phone may be easier to carry. If you care about photography, compare the cameras of the exact models you are considering instead of assuming every Pro phone is the same.
Set a comfortable budget before choosing a generation. A phone with more storage or a better battery reading may suit you better than a newer name with a condition note you do not want to live with. Our iPhone catalog lets you narrow the available devices by price, storage and carrier.
Choose storage for what you keep
Check how much space you use on your current phone. Photos, downloaded videos, games and offline music all count. Leave room for new files rather than choosing a replacement that is already close to full.
Compare the storage printed on each listing: 128GB, 256GB and 512GB are different configurations of the device. Cloud storage can help with some files, but it does not make every app or download disappear from the phone. Pick the capacity that works for your habits.
Read battery health alongside condition
When a battery-health percentage is listed, use it as one part of the comparison. It is not a promise of a fixed number of hours: your apps, signal strength, brightness and usage all affect your experience. Read the seller description and ask about any battery-related message on the device.
Apple also recommends checking a preowned iPhone for physical damage, battery condition and relevant parts or service information. Where a model supports it, review Parts and Service History in Settings. Do not treat a cosmetic description as a complete repair history.
Official reference: Apple: buying a preowned iPhone
Unlocked and carrier-specific are different
Read the carrier field before arranging pickup. A listing marked AT&T / Cricket or T-Mobile / Metro should be treated as carrier-specific; do not assume it is unlocked. An unlocked label also does not replace checking the exact device with your provider.
Tell us which company and plan you use. Confirm the SIM or eSIM requirements for that model with the carrier, and check the phone’s network-lock status in Settings. Carrier compatibility, Activation Lock and any finance or IMEI questions are separate checks.
Review the exact iPhone in person
Open the listing and examine every actual photo. Read any disclosed cracked glass, camera issue or other condition note, and review the seller-check section for that individual device. Ask about anything you want to understand before arranging pickup.
At pickup, try the display, touch response, cameras, microphone, speakers, buttons and charging connection. Check Face ID or Touch ID if the model has it. Confirm that the phone can be set up for you and is not blocked by another owner’s Activation Lock. Ask about accessories instead of assuming a charger or box is included.