Where the two releases stand today
iOS 26 is the finished, shipping release — the software the overwhelming majority of iPhones run, and the one that receives ordinary security updates on Apple's normal schedule. iOS 27 is the pre-release cycle running alongside it, moving through developer and public betas towards a public launch.
That difference in status matters more than any feature list. iOS 26 is what third-party apps are tested against; iOS 27 is what they will be tested against later. Anything that depends on an app working reliably today points towards staying put.
The compatibility gap
iOS 27 drops the iPhone XR, XS and XS Max, all of which run iOS 26. If you own one of those, the comparison is settled for you — iOS 26 is the last version your phone will receive, and it continues to get security updates. Our iPhone XR page covers the detail.
For everything from the iPhone 11 and iPhone SE (2nd generation) upwards, both versions are available and the choice is genuinely yours.
Apple Intelligence draws the real line
Neither release makes Apple Intelligence available on hardware that could not already run it. The cut-off remains the A17 Pro and later on iPhone, which means an iPhone 15 or iPhone 14 gains nothing on that front by moving to iOS 27.
If your phone is on the wrong side of that line, the practical gap between the two releases narrows considerably — you are comparing interface and system-app changes rather than a whole category of capability. Our device pages state which side each model falls on.
What you give up by moving early
Running iOS 27 before it ships means accepting the ordinary costs of a beta: apps that have not been updated yet, a first week of heavy background indexing and reduced battery, and the fact that you cannot restore an iOS 27 backup onto iOS 26 if you change your mind.
None of that is dramatic, but all of it is real, and it is the reason the honest recommendation for a main phone is to wait for the public beta to mature — or for the finished release. See our main-device guide.
How to move between them
Going forward is easy: enrol free at beta.apple.com and select the channel under Settings → General → Software Update → Beta Updates. Going back is not — it requires a recovery-mode restore from a signed IPSW and the archived backup you made beforehand.
That asymmetry is the whole decision in one sentence. Our downgrade guide covers the return trip in full.
Frequently Asked Questions
Should I upgrade from iOS 26 to the iOS 27 beta?
On a secondary device, yes. On your only phone, waiting for the public beta to mature or for the final release costs you very little and avoids the apps-not-ready period.
Which iPhones run iOS 26 but not iOS 27?
The iPhone XR, iPhone XS and iPhone XS Max. iOS 26 is their final version and continues to receive security updates.
Does iOS 27 add Apple Intelligence to older iPhones?
No. The hardware requirement is unchanged — A17 Pro and later. An iPhone 15 or 14 gains no Apple Intelligence features by moving to iOS 27.
Can I go back to iOS 26 after installing iOS 27?
Only via a recovery-mode restore from a signed IPSW, and only with your data if you made an archived backup before installing. An iOS 27 backup cannot be restored onto iOS 26.