Technology
When to Replace a Phone, and When Not To
Phones are sold on the assumption of a two-year cycle, and most people could comfortably run one for four or five. A phone that feels slow is usually not worn out — it usually has one specific fixable problem.
Here is how to tell the difference, and the one reason that genuinely does force a replacement.
The one reason that actually forces it
Security updates have stopped.
Everything else is a preference. This is not.
When a manufacturer stops issuing security updates, known flaws remain unpatched indefinitely. A phone in that state should not be used for banking, email or anything with a password.
How to check: open Settings and look for the software update screen. If it says the device is no longer supported, or if it has not received an update in more than a year while newer versions exist, that is your answer.
Manufacturers publish support periods. Apple typically supports phones for around five to six years; Android manufacturers vary enormously, from three years to eight depending on the maker and the model.
When support ends, replace it. Not immediately in a panic, but do not carry it for another two years.
The four things that feel like a dying phone and are not
1. The battery
By far the most common cause of "my phone is old and slow", and the cheapest to fix.
Batteries degrade with charge cycles. A phone that lasted a day when new and now needs charging by lunchtime has a worn battery, not a worn phone. Some phones also slow themselves deliberately to prevent shutdowns when the battery is degraded — which is experienced as the phone getting slower.
Check it: iPhone — Settings → Battery → Battery Health. Below about 80% capacity, replacement is worthwhile. Android varies by manufacturer; some show it under Settings → Battery, others require an app.
A battery replacement costs a fraction of a new phone and frequently makes it feel new. This is the single best piece of advice on this page.
2. Full storage
A phone with almost no free space slows down noticeably and behaves erratically.
Check: Settings → General → iPhone Storage, or Settings → Storage on Android.
What to clear: photos and videos, which are almost always the largest item; apps you have not opened in a year; downloaded podcasts and offline videos; message attachments, which accumulate invisibly for years.
Moving photos to cloud storage or a computer frees more space than anything else, and it is also the only way they survive the phone being lost.
3. Too many apps running in the background
Apps installed years ago and never used continue to update, sync and notify. Removing thirty of them noticeably improves both speed and battery.
Rule of thumb: if you have not opened it in a year, delete it. It can be reinstalled in a minute if you were wrong.
4. An old operating system, or a very new one
Updating an old phone usually helps. But the newest version of an operating system on the oldest phone that supports it sometimes runs poorly.
If the phone became sluggish immediately after a major update, and it is several years old, that is the cause — and there is not much to do about it beyond the other three fixes.
Reasons that are legitimate, but are preferences
The camera. Genuinely better on new phones, and worth it if photographs matter to you.
The screen size. A larger screen is easier to read, and a bigger phone is harder to hold. Both are real.
A cracked screen. Repairable, and worth pricing against the phone's value.
Apps that no longer work. Usually a symptom of the operating system being too old, which usually means support is ending anyway.
Wanting a new one. A legitimate reason and worth naming as what it is, rather than dressed up as necessity.
Reasons to be sceptical of
"It is more than two years old." Not a reason.
A carrier offering an upgrade. These are financing arrangements. Work out the total over the contract before treating it as a saving.
A shop diagnosing an unfixable fault in a phone with a worn battery. Ask specifically about the battery.
A pop-up warning about viruses. Phones do not work that way, and that message is itself a fraud. See fake emails for the same pattern in another medium.
If you are buying
Buy the previous model. Typically a substantial discount for changes most people will not notice, and it still has years of support ahead.
Check the support period before buying, not the specifications. It is the number that determines how long the phone is safe to use.
Consider refurbished from a reputable seller with a warranty. Frequently the best value available.
Do not buy more storage than you need, but do not buy the smallest option — running out is the cause of half the problems on this page.
Physical considerations matter more with age: weight, grip, whether you can reach across the screen one-handed. Hold it before buying if you can.
The order to try things
Before spending anything:
- Check whether security updates have stopped — if so, replace, and stop here
- Check battery health, and replace the battery if below 80%
- Clear storage until at least 15% is free
- Delete unused apps
- Restart the phone, which fixes more than people expect
Most phones that felt finished at step one are fine by step four, for the price of a battery.
For additional public information on everyday cybersecurity, see Cybersecurity and Infrastructure Security Agency.