What to Do When an IPSW File Becomes a RAR File

If your browser saved an IPSW file with a .rar extension, nothing is wrong with the download itself. Your operating system simply misread the file type. Here’s why it happens and how to fix it in under a minute.

Why It Happens

An IPSW file is internally a ZIP-style archive, so Windows and macOS sometimes guess its type from the archive signature instead of the extension, and guess “RAR.” The file is untouched; only the name is wrong.

The less common case: the file genuinely is a RAR archive, because an uploader or download manager compressed it. That one needs extracting, not renaming.

Step 1: Figure Out Which Case You Have

• File size matches the expected IPSW size (several GB, as listed on the download page): it’s almost certainly a mislabeled IPSW. Rename it (Step 2)
• File is much smaller than expected: it’s probably a real RAR archive containing the IPSW. Extract it (see “If It’s Genuinely a RAR Archive”)

Step 2: Rename the Extension

Windows:

1. In File Explorer, enable extensions: View > Show > File name extensions
2. Right-click the file and choose Rename
3. Change .rar to .ipsw
4. Confirm the warning prompt

Or from Command Prompt (first cd into the folder containing the file):

ren filename.rar filename.ipsw

macOS:

Select the file, press Return, change .rar to .ipsw, confirm. Or from Terminal (first cd into the folder containing the file):

mv filename.rar filename.ipsw

That’s usually the whole fix. If the extension doesn’t appear to change after renaming, restart the computer so the file-type cache refreshes.

Step 3: Alternative, Skip Renaming Entirely

Finder and iTunes mostly ignore extensions when you select a file manually:

1. Connect the device, open Finder (Mac) or iTunes (Windows)
2. Select the device, then hold Option (Mac) or Shift (Windows) and click Update or Restore
3. Pick the file in the dialog (even shown as .rar) and proceed

If the restore accepts it, the file was fine all along.

If It’s Genuinely a RAR Archive

If the file is far smaller than expected, extract it instead of renaming:

Windows:

1. Install 7-Zip (free)
2. Right-click the file and choose Extract Here

Mac:

1. Open the file with The Unarchiver or the built-in Archive Utility

Use the .ipsw file that comes out. One caution: only extract firmware from sources you trust, because an archive can contain anything, and firmware you flash is firmware you live with. Verify the checksum of the extracted file before installing.

If the File Is Actually Broken

Rename didn’t help, extraction fails, or the size is wrong in a bad way:

1. Delete the file and re-download from dotIPSW. Skip download managers, which are the most common source of corrupted or mislabeled downloads
2. Check the new file’s size against the listed size
3. Still failing? Try a different browser or network

A file that fails twice needs a different source, not a third attempt.

Preventing It Next Time

• Download directly from dotIPSW in a standard browser
• Check the extension right after the download finishes; fixing it takes five seconds while you remember what you downloaded
• Don’t let archive tools claim unknown file types during their installation

That’s the whole story: a .rar extension on an IPSW is cosmetic, and renaming it back takes less time than the confusion it causes.