How to Check That an IPSW File Is Genuine (SHA1 and Apple Servers)

IPSW files are large, often 7 to 10 GB. A download interrupted on a slow connection, or a file shared by someone on a forum, can be incomplete or modified. The result: errors during restore (for example 4013, 4005 or 14), or in rare cases a file that is not Apple's at all. Here is how to verify a file before using it.

Rule 1: download only from Apple's servers

Genuine IPSW files are hosted by Apple, usually at addresses starting with https://updates.cdn-apple.com/. Every download link on GetIPSW points directly to Apple's servers. Avoid files sent through WhatsApp, Telegram or file-sharing sites.

Rule 2: compare the checksum (SHA1)

A checksum is a fingerprint of the file. If one bit changes, the fingerprint changes. When a SHA1 value is published for a firmware (on its download page or in Apple's catalog), compare it with your downloaded file. You can also compute the checksum on two downloads of the same file: if they match, the download is intact.

On Windows

1. Open the folder containing the IPSW.
2. Click the address bar, type cmd and press Enter.
3. Type certutil -hashfile "filename.ipsw" SHA1 and press Enter.
4. Compare the result with the published value.

On Mac

1. Open Terminal.
2. Type shasum -a 1 (with a space), drag the IPSW file into the window and press Enter.
3. Compare the result.

If the values are different, download the file again. A download manager (or the browser's resume function) helps on unstable connections.

Rule 3: check the file size and name

• The size should match the one shown on the firmware page.
• The file name contains the model, version and build, for example iPhone17,1_27.0.1_24A446_Restore.ipsw. Make sure the model identifier matches your device: find your identifier.
• If Windows added .zip at the end, rename the file to .ipsw.

Why a genuine file is still refused

Even a perfect file is refused if Apple no longer signs it. Check with Signing Status before downloading. Common restore errors are explained in why your IPSW restore failed and errors 4005, 9 and 14.

Is a modified IPSW dangerous?

An iPhone verifies Apple's signature during installation, so a modified IPSW normally fails to install. But do not take the risk: a file from an unknown source can also contain malware for your computer. Stick to Apple's servers.