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The iPhone 15 line has four models — iPhone 15, 15 Plus, 15 Pro, and 15 Pro Max — and each needs its own IPSW firmware file matched to a model identifier. The wrong file will not restore, so this guide lists every iPhone 15 identifier, the current signed iOS build, and where to download the right IPSW.
Quick answer: all four iPhone 15 models currently run iOS 26.6.1 (build 23G83), the latest signed release. The previous build, iOS 26.6 (23G71), is also still signed. Find your model in the table below, then open its device page for the direct IPSW download.
iPhone 15 Model Identifiers
The identifier is the reliable way to match an iPhone 15 to its firmware — and, as with the iPhone 14, the numbers do not follow the marketing name in a straight line:
| Model | Identifier | Chip | Released |
|---|---|---|---|
| iPhone 15 | iPhone15,4 | A16 Bionic | Sept 2023 |
| iPhone 15 Plus | iPhone15,5 | A16 Bionic | Sept 2023 |
| iPhone 15 Pro | iPhone16,1 | A17 Pro | Sept 2023 |
| iPhone 15 Pro Max | iPhone16,2 | A17 Pro | Sept 2023 |
Mind the prefix jump. The standard iPhone 15 and 15 Plus use the iPhone15,x prefix (iPhone15,4 / iPhone15,5), but the iPhone 15 Pro and Pro Max jump to iPhone16,x (iPhone16,1 / iPhone16,2) — the same prefix later reused for the iPhone 16 Pro numbering scheme. Always confirm the full identifier before downloading, not just the leading number.
Currently Signed iOS Builds for iPhone 15
Apple only lets you restore or update to a signed build. At the time of writing, the signed builds for all four iPhone 15 models are:
| iOS Version | Build | Status |
|---|---|---|
| iOS 26.6.1 | 23G83 | Signed (latest) |
| iOS 26.6 | 23G71 | Signed |
Signing changes without warning — Apple usually stops signing the older build within days of a new release. Confirm status before you download: see how to check IPSW signing status and what a signed IPSW is.
Which Build Should You Install?
Install the newest signed build — here, iOS 26.6.1 (23G83). It carries the latest security fixes, and because 26.6.1 is a minor update over 26.6 there is no reason to stay on the older build unless you have a specific compatibility need. Once Apple stops signing 26.6, only 26.6.1 (and later) will be restorable.
How to Restore an iPhone 15 with an IPSW
The process is the same for all four models: back up your device, turn off Find My (Settings → your name → Find My → Find My iPhone), connect to a Mac or PC, and in Finder, the Apple Devices app, or iTunes hold Option (Mac) or Shift (Windows) and click Restore, then select the IPSW you downloaded for your identifier. All iPhone 15 models use USB-C, so a USB-C cable is required. If the iPhone is unresponsive, put it into recovery mode first. For signing rules and downgrade limits, see what a signed IPSW is.
iPhone 15 and iOS 27
All four iPhone 15 models are supported by the next major release. The iPhone 15 and 15 Plus use the A16 Bionic and the 15 Pro / Pro Max use the A17 Pro — both well within the supported range. Check the iOS 27 supported devices list for the full compatibility picture.
iPhone 15 vs iPhone 14 Firmware
Firmware is never shared across models — each iPhone needs an IPSW built for its own identifier, even when two models share a chip. The iPhone 15 and 15 Plus use the same A16 Bionic as the iPhone 14 Pro, but they still use different IPSW files and identifiers. If you own or are comparing an earlier model, see the iPhone 14 firmware guide and the iPhone 16 firmware guide.
All iPhone 15 Firmware Downloads
Open your model's device page for the live list of signed IPSW files:
- iPhone 15 (iPhone15,4)
- iPhone 15 Plus (iPhone15,5)
- iPhone 15 Pro (iPhone16,1)
- iPhone 15 Pro Max (iPhone16,2)
You can also browse every model from the iPhone firmware page.
iPhone 15 Firmware FAQ
What is the latest iOS version for iPhone 15?
All four iPhone 15 models run iOS 26.6.1 (build 23G83), the current signed release. iOS 26.6 (23G71) is also still signed at the time of writing.
What are the iPhone 15 model identifiers?
iPhone 15 is iPhone15,4, iPhone 15 Plus is iPhone15,5, iPhone 15 Pro is iPhone16,1, and iPhone 15 Pro Max is iPhone16,2.
Why is the iPhone 15 Pro identifier iPhone16,1?
Apple's internal identifier numbers do not track the marketing name. The iPhone 15 Pro and Pro Max were assigned the iPhone16,x prefix, while the standard iPhone 15 and 15 Plus use iPhone15,4 and iPhone15,5. Always match the full identifier rather than the leading number.
Do all four iPhone 15 models use the same firmware?
No. Each model has its own IPSW tied to its identifier. An iPhone 15 Pro IPSW will not restore an iPhone 15, even though both are "iPhone 15" devices.
Which chip does each iPhone 15 model use?
The iPhone 15 and iPhone 15 Plus use the A16 Bionic; the iPhone 15 Pro and 15 Pro Max use the A17 Pro. All four are supported by current iOS.
Can I downgrade my iPhone 15 to an older iOS version?
Only to a build Apple is still signing. Once a version is unsigned it can no longer be restored, so your options are limited to the currently signed builds shown on your model's device page.
Do I need a USB-C cable to restore an iPhone 15?
Yes. The iPhone 15 line switched to USB-C, so you connect it to a computer with a USB-C cable (USB-C to USB-C, or USB-C to the port your computer provides).
Will iPhone 15 get iOS 27?
Yes. All four iPhone 15 models are within the supported range for the next major release. See the iOS 27 supported devices list for confirmation.