A power strip and a surge protector look identical and cost very differently. One just multiplies outlets; the other actually absorbs voltage spikes that can damage electronics — for a limited number of hits, after which it silently becomes a power strip again. This guide explains joules, indicator lights, what a surge protector can’t do, and how to protect a home office properly.
Quick answer
- Buy: a surge protector with a UL 1449 listing, a protection indicator light, and a joule rating in the thousands for computer gear.
- Replace it after a major surge, or every few years — protection wears out.
- It won’t help with blackouts. That’s a UPS.
- Never daisy-chain strips, and never plug a heater or a laser printer into one.
Power strip vs. surge protector vs. UPS
| Protects from spikes | Keeps power during an outage | Corrects low voltage | |
|---|---|---|---|
| Power strip | No | No | No |
| Surge protector | Yes, up to its rating | No | No |
| UPS (line-interactive) | Yes | Yes, minutes | Yes (AVR) |
How to read the specs
- Joule rating: roughly how much surge energy the unit can absorb over its life. Higher is better; aim well into the thousands for computers and monitors.
- UL 1449 listing (or the equivalent standard where you live) means it was tested as a surge protective device, not just as an extension cord.
- Clamping voltage: the level at which it starts diverting. Lower means it acts sooner.
- Response time: quoted in nanoseconds; faster is better, though differences are small between reputable models.
- Protection indicator LED: essential — it’s the only way to know the protection is still alive.
- Connected equipment warranty: a manufacturer promise to cover damaged gear. Read what it actually requires.
The part nobody mentions: they wear out
Most surge protectors work using components that sacrifice themselves a little with every spike. After enough events — or one big one — the protection is gone, but the outlets still deliver power. Without an indicator light, you’d never know. Treat a surge protector as a consumable: check the LED occasionally, and replace the unit after a significant electrical event or after a few years of service.
Practical layout for a desk
| Device | Where to plug it |
|---|---|
| Desktop PC, monitor, NAS, modem, router | UPS battery outlets |
| Laptop charger, speakers, desk lamp, phone chargers | Surge-protected outlets |
| Laser printer, space heater, vacuum | Directly into a wall outlet |
Also protect the paths that carry surges into your equipment: coaxial and Ethernet lines from outside the building. Some surge protectors include pass-through jacks for exactly that reason.
Features worth paying a little more for
- Widely spaced outlets so chunky power bricks don’t block neighbours — or a model with rotating outlets.
- Flat plug and a long cord for desks pushed against a wall.
- Built-in USB-C PD ports to cut down on adapters.
- Mounting keyholes so it can be fixed under the desk, out of the dust — see our cable management guide.
- Individually switched outlets to cut standby power for things you use occasionally.
Safety rules
- Never plug one strip into another.
- Don’t run a strip under a rug or where it can be stepped on.
- Don’t exceed the strip’s total current rating — add up what’s plugged in.
- Replace anything with a damaged cord, a warm housing or a burning smell immediately.
- For lightning-prone areas, ask an electrician about a whole-house surge protective device; the strip is the last line of defence, not the first.
Power protected, data isn’t: make sure you also have backups — see how to back up your computer.