Download IPSW
IPSW.io lists Apple firmware (IPSW) files by device and iOS version, so you can restore or update an iPhone, iPad, iPod touch or Mac from your computer. Pick your model, choose a version, and follow the guide for Finder, iTunes or Apple Devices.
Product
IPSW is the file format Apple uses to install or restore iOS, iPadOS, tvOS, visionOS and HomePod software, and macOS on Apple silicon Macs. You open the file with Finder on a Mac, iTunes or the Apple Devices app on Windows, or Apple Configurator for Macs.
Following these steps will ensure your data remains safe during the update. However, I still recommend backing up your device beforehand as a precaution.
Learn how to backup your iPhone and iPad
iTunes will automatically cancel the process if it detects an incompatible file for your device. The only downside is having to download the correct file again, so please double-check before proceeding.
Yes. Download the IPSW for your exact device model, then choose it in Finder, iTunes or the Apple Devices app when you restore or update (hold Option on a Mac or Shift on Windows while you click the button). Apple must still be signing that iOS version, and the file must come from a trusted source.
You're not downloading the files from my server—you're downloading them directly from Apple. This is evident from the download URLs, which point to Apple’s official IPSW hosting domain: updates.cdn-apple.com. Additionally, if these files were altered in any way, iTunes or Finder would reject them, since modified IPSW files cannot be installed.
A release candidate (RC) is typically the final beta build before a major release of the software to customers. Apple makes it available so developers can test it before the public release.