The following method of entering the DFU mode has been used by Apple (by using the same button combination) since the iPhone 8, 8 Plus and X. If you’re coming from an iPhone 7 or earlier, you’ll find this new button combination to be more complicated than before.
Here are the requirements to enter DFU (device firmware update)
Windows or Mac computer.
Latest version of iTunes installed or if you’re using a Mac, macOS Catalina.
Lightning to USB or Lightning to USB-C cable.
Before you begin, you should know that DFU mode erases your iPhone’s data. If you want your photos, texts, documents, or other data saved, you’ll need to back it up through iTunes or iCloud first.
Sometimes you just need to identify exactly the device your are holding in your hands to see its specs, features or just to simply know the exact firmware you need to download in order to restore your iPhone, iPad, iPod or AppleTV.
getiOS.com is here to help you; we’ve included in our website a very simple and easy way to do that. Follow this link to get to the iDevice identifier. Just look up the A-model printed on your iDevice and insert it in the search box. We’ll provide useful information about your iDevice in seconds.