iOS 26.7.1 or iOS 27: Which Should You Install on Your iPhone?

Open Settings > General > Software Update on an iPhone still running iOS 26 and you will probably see two choices: a small security update, iOS 26.7.1, and a big upgrade, iOS 27. Which one should you pick? It depends on your phone and on what matters most to you.

Why Apple offers two updates

Since iOS 15, Apple lets people stay on the previous version for a while and still receive security fixes. iOS 26.7.1, released on September 28, 2026, is one of those fixes. It closes a CoreGraphics vulnerability (CVE-2026-86950) that Apple says "may have been exploited in an extremely sophisticated attack against specific targeted individuals". In other words, it is a real, serious security hole.

iOS 27, released on September 14, is the new major version with new features and a refreshed design.

The most important rule

Do not stay on an older iOS 26 version. If you remain on iOS 26, install iOS 26.7.1 now. If you move to iOS 27, always install the latest iOS 27 update. The only bad choice is to ignore security updates.

Choose iOS 26.7.1 if...

• You have an older iPhone such as an iPhone 11, iPhone SE (2nd generation) or iPhone 12. These models support iOS 27, but the newest features need more powerful chips and the first versions of a major update are often heavier on older batteries.
• You rely on a specific app for work, banking or mobile money that has not yet confirmed iOS 27 support.
• You want to wait for the first fixes. Many users wait for the x.1 or x.2 version (iOS 27.2 is expected in October) before upgrading.
• You want to keep the option open. Once you install iOS 27, you cannot return to iOS 26. Apple stopped signing iOS 26.6.2 on September 21. See why the downgrade window is closed.

Choose iOS 27 if...

• You have an iPhone 15 Pro or newer and want the new Siri. The redesigned Siri, which understands natural conversation and what is on your screen, requires an iPhone 15 Pro or later.
• You want the speed improvements. Apple says apps can launch up to 30% faster and AirDrop transfers are up to 80% faster on iOS 27.
• You want the new tools: Photos "Extend" and "Spatial Reframe", Safari tab grouping, calendar events created from plain sentences, and stronger parental controls such as "Ask to Browse".
• You bought a new iPhone 18 Pro: it ships with iOS 27 and cannot run iOS 26.

Quick decision table

• iPhone SE (2nd/3rd gen), 11, 12: iOS 26.7.1 for now, iOS 27 after 27.2.
• iPhone 13, 14, 15, 15 Plus: either is fine. Choose iOS 27 if your important apps support it.
• iPhone 15 Pro, 16, 17 and newer: iOS 27.0.1 to get the new Siri and features.

To check the newest version your model can run, use our Max OS Version tool.

How to choose the update on your iPhone

1. Back up your iPhone first (how to back up).
2. Go to Settings > General > Software Update.
3. To stay on iOS 26, tap the iOS 26.7.1 update. The iOS 27 upgrade appears below as a separate option ("Also Available"). Do not tap it.
4. To move to iOS 27, tap Upgrade to iOS 27.
5. Turn off Automatic Updates > iOS Updates if you do not want your iPhone to upgrade to iOS 27 on its own at night.