Find out where your model actually stands
Software Update never offers a version your iPhone cannot run, so the absence of an update usually means your model has reached its ceiling rather than that something is broken. Settings → General → About shows the version you are on.
Our compatibility checker gives your exact model's answer in one step, and each result links to a full page covering what that iPhone runs, what it stopped at and why. Our support lifespan data shows how many major versions each model received.
Security updates continue after features stop
Apple keeps issuing security patches for older release lines after they stop receiving new features, sometimes for years. These arrive through the same Settings → General → Software Update screen and are small and quick.
This is the most important thing to know: staying current on your last supported version is a genuinely supported position, not a dead end. Check Software Update periodically even when you know no new version is coming.
What actually degrades over time
Not the phone — the ecosystem around it. App developers eventually raise their minimum iOS version, so apps stop receiving updates and then stop installing at all. Some websites drop support for older Safari versions. Banking and authentication apps tend to move first, because their security requirements are strictest.
That process is gradual and takes years. An iPhone two versions behind is barely affected; one five versions behind starts to feel it.
Getting the last update it can take
If your iPhone has been off for a long time, it may be several versions behind its own ceiling. Charge it, connect to Wi-Fi and run Software Update repeatedly — iOS sometimes steps through intermediate versions rather than jumping straight to the last one.
If it has too little free space to update, connect it to a computer and update through Finder or the Apple Devices app, which needs far less room on the device — see our computer update guide.
What not to do
There is no file, profile or tool that installs a newer iOS on an unsupported iPhone. The check happens inside the installer against the device model, and nothing you can download changes it. Sites offering one are offering something that cannot work — our piece on what those downloads actually contain covers the risk.
Jailbreak-based approaches trade the device's security model for a cosmetic version number and break the security updates that are the main reason to keep the phone current. On a phone you actually use, it is a bad trade.
Frequently Asked Questions
Can I install a newer iOS on an unsupported iPhone?
No. The compatibility check happens in the installer against the device model, and no file, profile or tool changes it.
Does an old iPhone still get security updates?
Yes, often for years after it stops receiving new features. They arrive through the normal Software Update screen.
What stops working on an old iPhone?
Apps gradually raise their minimum iOS version and stop updating, then stop installing. Banking and authentication apps usually move first.
How do I know which iOS version is my iPhone's last?
Our compatibility checker gives the answer for your exact model, along with what it runs and where it stopped.