How to actually tell if you need to upgrade your phone
Two numbers decide it, and neither of them is the model year. Everything else is preference dressed up as necessity.
Phone upgrade advice is mostly written by people with something to sell. The result is a genre built around comparisons — this year's camera against last year's, this chip against that one — which reliably produces the feeling that your phone is old without ever establishing that it is failing.
There are exactly two numbers that determine whether a phone genuinely needs replacing. Both are free to check, both take under a minute, and both are ignored by almost every upgrade guide because neither of them changes annually.
On this page
Number one: battery health
Battery health is the percentage of original capacity a battery can still hold. It is the single best predictor of whether a phone will feel slow, and it explains most of the "my phone got worse after an update" complaints that get blamed on software.
On iPhone: Settings → Battery → Battery Health & Charging. The figure is labelled Maximum Capacity.
On Android: it depends. Some manufacturers surface it in Settings → Battery → Device care or a diagnostics menu; many bury it or omit it entirely, in which case a third-party app such as AccuBattery estimates it over a few charge cycles.
| Battery health | What you will notice | What to do |
|---|---|---|
| 90–100% | Nothing. This is a healthy battery. | Nothing. |
| 80–89% | Shorter days, especially in cold weather. | Monitor. No action needed. |
| Below 80% | Sudden shutdowns, and noticeable slowdown as the system throttles to prevent them. | Replace the battery, not the phone. |
| Below 70% | Unreliable through a normal day. | Replace the battery now, or the phone if it is also out of support. |
The 80% threshold is not arbitrary. Below roughly that point, an ageing cell can no longer supply peak current without its voltage sagging far enough to cause an abrupt shutdown. Both iOS and Android respond by limiting peak performance — deliberately, and for good engineering reasons. The phone is not worn out. Its battery is.
Why this gets misdiagnosed as "the update slowed my phone"
Throttling tends to begin around the same time as a major OS release, because that is when people notice anything at all. The correlation is real and the causation is not. Check the battery figure before blaming the software.
Number two: the security update cutoff
The second number is the date your manufacturer stops shipping security patches. This matters far more than whether you get the next feature release, and it is the one genuinely non-negotiable reason to replace a working phone.
A phone that no longer receives patches keeps working perfectly. It also stops receiving fixes for vulnerabilities that are, by then, publicly documented. The risk is not that your phone stops functioning; it is that it keeps functioning while known holes stay open — in the browser engine, in the media parsers that handle every image and video that arrives in a message, in the modem stack.
Feature updates are a preference. Security updates are the support window that actually ends.
How long each brand actually supports a phone
Support windows have lengthened dramatically, and they are now a legitimate purchase criterion rather than small print.
| Brand | Typical support window | Notes |
|---|---|---|
| Apple | Around 5–7 years | Not formally promised as a number; historically among the longest in practice. |
| Google Pixel | 7 years (Pixel 8 onward) | Earlier Pixel 6–7 generations: about 5 years. |
| Samsung | Up to 7 years on flagships | Mid-range A-series typically 5–6; older budget models far less. |
| Motorola | Highly variable | Up to 7 years on top models, as little as 1–2 on older Edge and Razr devices. |
Two cautions. First, these are the windows advertised for phones sold now; the phone in your pocket was sold under whatever policy applied then, which was usually shorter. Second, the clock generally starts at the model's launch, not at your purchase. Buying a two-year-old handset at a discount often means buying a device that is two years into its support window.
What is not a reason to upgrade
- A new model exists. Year-over-year camera and chip gains are now small enough that they are difficult to see outside a side-by-side comparison, which is the only place they are ever shown to you.
- Storage is full. Offload photos to cloud or local backup first. This is a filing problem wearing an upgrade costume.
- The phone feels slow but the battery is above 85%. Try a restart, check what is running in the background, and clear the browser cache. If that fixes it, it was never the hardware.
- A cracked screen. A screen repair on a phone still in its support window is almost always the cheaper decision.
- The carrier offered a deal. Trade-in offers are priced to be attractive at the moment your phone still has resale value to the carrier. That is a fact about their margin, not about your phone.
The repair that buys you two more years
If your battery is below 80% but the phone still receives security updates, a battery replacement is the highest return-on-cost repair in consumer electronics. It restores full performance — because the throttling stops — and typically costs a small fraction of a replacement handset.
Two things to check first. Confirm the phone still has meaningful support window left; putting a new battery in a phone with three months of patches remaining is money spent twice. And check whether your device pairs its battery to the mainboard, in which case a third-party replacement may leave a permanent warning or disable health reporting. Our guide to repair rights by state covers what that means and where the law helps.
The decision, in four steps
- Check battery health. Below 80%? The battery is the problem, not the phone.
- Check your manufacturer's published support window against your model's launch date.
- Still in support, battery below 80% → replace the battery.
- Out of support → replace the phone. In support with a healthy battery → keep it, whatever this year's launch event suggested.
If you land on replacing the phone, a manufacturer-certified refurbished unit one generation back usually gives you most of the remaining support window at a considerably lower price — our guide to refurbished grading explains which tiers are worth buying.