The short answer
A plain power strip gives you more sockets and no protection at all. A surge protector contains components that absorb voltage spikes, and they wear out — a unit that has taken several surges may be providing nothing while still powering your devices. Check for a protection indicator light.
We may earn a commission when you buy through links on this page, at no extra cost to you.
Surge protection is one of those purchases where the cheap version and the useful version look identical on a shelf. The difference is inside, and it matters most for the equipment you would least like to replace.
What a surge protector actually does
It diverts excess voltage away from your devices, usually using components called metal oxide varistors. Those components degrade every time they absorb a spike. This is the crucial and least understood point: surge protectors have a finite lifespan measured in the energy they have absorbed, not in years. A ten-year-old unit in an area with frequent spikes may be a plain power strip by now.
Good units include an indicator light showing protection is still active. If yours has one and it is off, replace it. If yours has no indicator at all, you have no way of knowing.
The one specification worth reading
The joule rating tells you how much energy the unit can absorb over its life. Higher is better and means longer service, not stronger protection at any given moment.
- Under 500 joules — minimal, suitable for lamps and phone chargers.
- 500 to 1,000 joules — reasonable for a television or a console.
- 1,000 to 2,000+ joules — what a desktop computer, a home office or an AV rack deserves.
Also look for a clamping voltage figure, where lower is better, and a response time in nanoseconds.
A sensible everyday option
Surge protector power strip with 8 outlets and USB ports
The practical case for something like this is the combination of enough spaced sockets for chunky power bricks, USB charging built in, and a flat plug that lets furniture sit closer to the wall. Check the joule rating on the listing and treat anything under 500 as suitable only for low-value devices.
What it does not protect against
- A direct lightning strike. Nothing at this price does. If a storm is overhead, unplugging is the only real protection.
- Power cuts and brownouts. A surge protector does not keep anything running. For that you need a UPS, which is a different product with a battery inside.
- Surges arriving by other routes — aerial, phone line or Ethernet. Units with coaxial and network passthrough exist for that.
Plugging one strip into another is a genuine fire risk and it compromises the protection circuitry. Equally, do not run high-draw appliances such as heaters, kettles or washing machines through a surge protector — they belong directly in a wall socket.
Where protection is actually worth it
Prioritise by what is expensive and what is hard to replace: a desktop computer with your files on it, a television, a games console, a router and modem, and anything with a hard drive. A phone charger does not need it, and neither does a lamp.
If you live somewhere with frequent storms or an unstable supply, a UPS on the computer is a better investment than a better surge protector, because it handles both spikes and the abrupt power loss that corrupts data.
Frequently asked questions
How long does a surge protector last?
It depends on how many surges it has absorbed rather than on age alone. Three to five years is a common guideline, sooner in areas with an unstable supply. An indicator light is the only reliable way to know.
Is a power strip the same as a surge protector?
No. A power strip only splits one socket into several. Surge protection is a separate feature that must be stated on the packaging, usually with a joule rating.
Will a surge protector stop my PC turning off in a power cut?
No. That needs an uninterruptible power supply, which contains a battery and gives you a few minutes to save and shut down properly.
Do I need surge protection for a laptop?
Less than for a desktop, because the power brick provides some isolation and the battery rides out brief interruptions. It is still worth protecting a docking setup with monitors and drives attached.
Check whether your current strip has a protection light, and whether it is lit. Plenty of people discover they have been unprotected for years.
