Apple Firmware Signing Database

iOS Signing Status Checker

Instantly verify whether Apple is still signing a firmware for your device. Look up by device identifier or iOS version — before you attempt a restore or downgrade.

LiveSigning Data
iOS 1–26Version Coverage
AlliPhone & iPad
0Lookups Today
How It Works

Two ways to check
firmware signing status.

01
By Device

Enter your device identifier — e.g. iPhone17,2 — and see every firmware version with its current signing status in one table.

02
By iOS Version

Enter an iOS version — e.g. 18.0.1 — and see which devices Apple is still signing it for, and which have been cut off.

03
Read Signing Status

A Signed badge means Apple accepts this firmware right now. Unsigned means restores to that version are no longer possible.

04
Download IPSW

Click the download icon next to any firmware to access its full IPSW restore file details, checksums, and direct download link.

Signing Status Checker

Check your firmware.

signing_checker — live apple signing status

Find your device identifier in Settings → General → About → Model Number (tap to reveal hardware model).

Try: iPhone17,2  ·  iPad16,1  ·  iPhone12,1

Querying Apple signing servers…

Could not fetch signing data. Check the identifier and try again.

—
— iOS
All Firmware
iOS Version Build ID Status Release Date Actions
—
Build ID: —
0
Signed
0
Unsigned
0
Total Devices
Deep Dive

Understanding iOS firmware
signing & why it matters.

~72h
Avg. Signing Window
1–3
Versions Signed at Once
0
Ways Around It (officially)
signing_lifecycle.sh
$ query signing_window iOS 18.2 Checking Apple TSS servers... ✓ iOS 18.2 — SIGNED (22C152) Released: Dec 11, 2024 Window: ~3 days post-18.2.1
$ query signing_window iOS 18.1 Checking Apple TSS servers... ✗ iOS 18.1 — UNSIGNED (22B83) Closed: ~72h after 18.2 drop Restore: Not possible
$ explain tss_ticket --verbose TSS = Tatsu Signing Server (Apple) iTunes/Finder sends ECID + nonce Apple returns signed blob (shsh2) No blob = restore rejected
$ save_blobs iPhone17,2 iOS 18.2 ✓ SHSH2 blob saved locally Tool: blobsaver / shsh2 Use: Future downgrades (if exploit)
$
What Is Firmware Signing?

Every time you restore or update an iPhone or iPad, Apple's servers cryptographically verify the firmware before it's installed. This verification process — called TSS (Tatsu Signing Server) checking — means Apple can control exactly which software versions run on its hardware at any given moment. If Apple is no longer "signing" a version, restoring to it becomes impossible through normal means, even if you have the IPSW file.

The Signing Window Timeline
New iOS Release
Apple releases a new version. Both the new version and the previous version are typically signed simultaneously for a short window.
~48–72 Hours Later
Apple closes signing for the older version. After this point, only the new (and sometimes one prior) version can be restored to.
Window Closed
The old firmware is permanently unsigned. You cannot restore to it via iTunes, Finder, or any official method — regardless of whether you have the IPSW file saved.
SHSH2 Blobs — Save Before It Closes

An SHSH2 blob is a signed ticket from Apple's TSS servers tied to your specific device's ECID (unique hardware ID) and a particular firmware version. If you save blobs while a version is still being signed, you may be able to use them later with tools like futurerestore — but only if a compatible bootchain exploit exists. Tools like blobsaver can automatically save blobs for all currently-signed versions.

blobsaver shsh2 CLI futurerestore ECID required Per-device
Why Does This Matter for Jailbreakers?

Most jailbreaks target a specific iOS version range. If you accidentally update past the jailbreakable window, you cannot go back once Apple closes signing. Checking signing status before updating lets you make an informed decision — stay on a jailbreakable version or accept you'll lose root access. The window can close within hours of a new release.

✓ Signed = can restore / downgrade ✗ Unsigned = locked out permanently
More Tools

Everything you need for
iOS device research.

A full suite of iOS lookup tools — identify any device, check jailbreak compatibility, and now verify signing status — all in one place.

Model iPhone17,2 Identified
Name iPhone 16 Pro Max
Chip Apple A18 Pro
Released September 2024
Device Lookup
Device Identifier

Instantly decode any iPhone or iPad hardware model identifier. Enter a model string like iPhone17,2 and get the full device name, chip, storage options, release date, and technical specifications in seconds.

All iPhone models All iPad models iPod touch Chip details Release dates Instant results
Identify a Device
iOS 16.0–16.5.1 Jailbreakable
Tool Dopamine
iOS 17.x Limited
iOS 18.x No Public JB
Jailbreak Research
Jailbreak Compatibility

Find out exactly which iOS versions are jailbreakable on your device, which tools to use, and whether a public exploit exists right now. Covers checkm8, Dopamine, palera1n, unc0ver, and every major tool from iOS 1 through iOS 18.

checkm8 / palera1n Dopamine unc0ver iOS 1–18 coverage Per-device lookup Tool recommendations
Check Jailbreak Status
iOS 18.3.2 Signed ●
iOS 18.3.1 Unsigned
iOS 18.3 Unsigned
iOS 18.2.1 Unsigned
You Are Here
Signing Status Checker

Check in real time whether Apple is currently signing a specific iOS firmware for your device — or see which devices a version is signed for. Essential before any restore, downgrade, or jailbreak attempt. Data is live from Apple's TSS servers.

Live TSS data By device By iOS version IPSW details Checksums Direct download
Back to Top
FAQ

Frequently asked questions.

Everything you need to know about iOS signing status, firmware windows, and how to use this tool.

Signed means Apple's TSS (Tatsu Signing) servers will approve a restore to that firmware version right now. When you initiate a restore, your device sends its unique ECID identifier along with the firmware request — Apple signs off on it and the install proceeds.

Unsigned means Apple's servers will reject any restore attempt to that version. Even if you have the exact IPSW file saved to your computer, iTunes or Finder will return an error (typically error 3194) because Apple refuses to countersign the installation.
Apple typically keeps the previous version signed for 48–72 hours after a new release, though this varies. Sometimes Apple closes signing within hours, especially for security-critical updates. In rare cases a version may remain signed for several days. There is no official announcement — the window simply closes without warning, which is why monitoring signing status in real time is important if you want to stay on a specific version.
No, not through normal means. Having the IPSW file is necessary but not sufficient. The restore process requires Apple's live TSS authorization regardless. However, there are two exceptions:
  • SHSH2 blobs + futurerestore: If you saved SHSH2 blobs while the version was signed AND a compatible bootchain exploit exists (like checkm8 for A11 and older), you may be able to restore using futurerestore.
  • checkm8 devices: The checkm8 bootrom exploit on A5–A11 chips allows restoring to specific versions even without Apple's live signing, given the right tools and blobs.
There are a few methods:
  • On device: Go to Settings → General → About → Model Number. Tap the field to toggle between the marketing part number (e.g. MY6F2LL/A) and the hardware model identifier (e.g. iPhone17,2).
  • Via iTunes/Finder: Connect your device and check the Summary pane — it will display model information you can cross-reference.
  • Via System Information (Mac): With device connected, Apple menu → About This Mac → System Report → USB → find your device.
IPSW stands for iPhone Software (a naming holdover from the iPod era). It's a ZIP archive containing the complete iOS firmware for a specific device — the operating system, bootloaders, and restore ramdisk.

To use an IPSW: open iTunes (Windows) or Finder (macOS Catalina+), connect your device, hold Option (Mac) or Shift (Windows) and click "Restore iPhone…", then select your downloaded IPSW. The restore will fail if Apple is not currently signing that version.
The version number (e.g. 18.2.1) is the human-readable release designation you see in Settings. The build ID (e.g. 22C161) is Apple's internal identifier that uniquely distinguishes each firmware build — including carrier variants, regional builds, or re-releases with the same version number but different code.

Build IDs matter because multiple IPSWs can share a version number but differ by device or region. When saving SHSH2 blobs or verifying signing status, the build ID is the precise reference point.
Only if Apple is still signing the older version. If the version you want is currently signed (shown with a green badge in this tool), you can restore to it via iTunes or Finder right now — no jailbreak needed. Simply download the IPSW for your device and restore using the Shift/Option+Restore method.

Once Apple closes signing, a standard downgrade is impossible without a bootrom-level exploit or saved SHSH2 blobs combined with an applicable tool.
This tool queries live signing data in real time via the IPSW.me API, which polls Apple's TSS servers continuously. Status changes are typically reflected within a few minutes of Apple closing or opening a signing window. Because the data is live, every lookup you perform reflects the current state — not a cached snapshot. This makes the checker reliable even during the narrow signing windows that follow a new iOS release.
Checksums are cryptographic fingerprints that let you verify your downloaded IPSW file is complete and unmodified. After downloading, compare the file's checksum against the values shown in the firmware detail panel:
  • SHA-256 is the most reliable — use this when available.
  • SHA-1 is widely used in the iOS community and legacy tools.
  • MD5 is the fastest to compute but weakest cryptographically.
On macOS: shasum -a 256 filename.ipsw. On Windows: certutil -hashfile filename.ipsw SHA256.
Yes, sometimes. Apple signs firmware per-device, not per-version globally. It's possible (and has happened) that a specific iOS version is signed for newer devices but unsigned for older ones, or vice versa. This is most common with:
  • Security patches that apply only to certain chip generations
  • Older devices reaching end-of-life support
  • Regional or carrier firmware variants
This is why the "By iOS Version" tab in this tool shows signing status broken down per device — always check for your specific model.
A full IPSW restore via iTunes/Finder will erase all data on the device. This is a factory reset — all apps, settings, photos, and files are wiped before the new firmware is installed. Always back up to iCloud or via Finder/iTunes before restoring.

OTA (over-the-air) updates do not erase data. But OTA updates can only go to newer versions — they cannot downgrade. For a downgrade, a full restore is required, which means data loss unless you restore from a backup afterwards.
Apple's build IDs follow a pattern: [OS major][OS minor][Revision]. For example, 22C161:
  • 22 — corresponds to iOS 18 (internal build era)
  • C — the minor version letter (A = .0, B = .1, C = .2, etc.)
  • 161 — internal revision number within that minor release
Build IDs with the same letter but different numbers are typically re-releases or carrier-specific variants. Higher revision numbers within the same letter are usually incremental bug fixes. Build IDs starting with letters further in the alphabet correspond to newer major iOS versions.