Best Smoke & CO Detectors for DIYers
Working smoke and carbon-monoxide alarms are the cheapest life-safety upgrade in any home. The choices are combo (smoke + CO) versus separate, battery versus hardwired, and basic versus smart with phone alerts. Every home needs them on every level.
What to look for
- ·Put smoke alarms on every level and in/near every bedroom; add CO alarms near sleeping areas and on each level, especially near fuel-burning appliances and garages.
- ·Combo smoke + CO units cover both in one device; choose 10-year sealed-battery models to avoid yearly battery changes, or hardwired with battery backup.
- ·Smart alarms add phone alerts, voice location, and interconnection so all units sound together, useful for larger homes and remote awareness.
Quick comparison
| Product | Tier | Price | Best for |
|---|---|---|---|
| First Alert SMCO100V Smart Combo | Editor's pick | $40 to $70 | Smart combo coverage |
| Kidde Smart Smoke + CO | Editor's pick | $40 to $70 | Connected full-feature |
| First Alert 10-Year Hardwired Combo | Editor's pick | $30 to $55 | Hardwired interconnect |
| First Alert Hardwired Smoke + CO | Best value | $25 to $45 | Value hardwired combo |
| Kidde Smoke + CO Combo | Best value | $25 to $45 | Dependable value combo |
| First Alert 10-Year Battery Alarm | Best value | $18 to $35 | No-battery-change value |
| First Alert Basic Smoke Alarm | Budget pick | $10 to $20 | Budget smoke coverage |
| Kidde Basic Smoke Alarm | Budget pick | $8 to $18 | Budget multi-pack |
| First Alert Plug-In CO Detector | Budget pick | $15 to $30 | Budget CO coverage |
Editor's pick
First Alert SMCO100V Smart Combo
$40 to $70
A smart smoke and CO combo with voice and location alerts at a more affordable price than premium smart alarms, a great Nest alternative. The pick for smart coverage value.
Best for: Smart combo coverage
Typically available at Home Depot, Amazon.
Kidde Smart Smoke + CO
$40 to $70
A top-rated smart combo with voice alerts, Alexa and Google support, and push notifications. The pick for connected, full-feature life safety.
Best for: Connected full-feature
Typically available at Home Depot, Amazon.
First Alert 10-Year Hardwired Combo
$30 to $55
A hardwired, interconnected smoke and CO combo with a 10-year sealed battery backup so all units sound together. The pick for whole-home hardwired safety.
Best for: Hardwired interconnect
Typically available at Home Depot, Lowe's.
Best value
First Alert Hardwired Smoke + CO
$25 to $45
A reliable hardwired combo alarm with battery backup at a value price. A strong value for newer homes wiring all alarms to sound together.
Best for: Value hardwired combo
Typically available at Home Depot, Lowe's, Amazon.
Kidde Smoke + CO Combo
$25 to $45
A dependable battery or hardwired smoke and CO combo from a trusted brand at a fair price. A solid mid-value pick for full coverage.
Best for: Dependable value combo
Typically available at Home Depot, Amazon.
First Alert 10-Year Battery Alarm
$18 to $35
A sealed 10-year-battery smoke (or combo) alarm that never needs a battery change for its life. A great value that removes the yearly battery chore.
Best for: No-battery-change value
Typically available at Home Depot, Lowe's, Amazon.
Budget pick
First Alert Basic Smoke Alarm
$10 to $20
A simple, reliable battery smoke alarm at a low cost to cover every level and bedroom. The budget essential for basic fire detection.
Best for: Budget smoke coverage
Typically available at Home Depot, Walmart, Amazon.
Kidde Basic Smoke Alarm
$8 to $18
An affordable, dependable smoke alarm in value multi-packs to outfit a whole home cheaply. A budget pick for complete smoke coverage.
Best for: Budget multi-pack
Typically available at Home Depot, Amazon.
First Alert Plug-In CO Detector
$15 to $30
A simple plug-in carbon-monoxide detector with battery backup for near sleeping areas and appliances. A cheap, easy way to add essential CO coverage.
Best for: Budget CO coverage
Typically available at Home Depot, Lowe's, Amazon.
Frequently asked
How many smoke and CO detectors do I need?+
Code generally calls for a smoke alarm on every level of the home, inside each bedroom, and outside each sleeping area. Carbon-monoxide alarms go near sleeping areas and on each level, especially near furnaces, water heaters, fireplaces, and attached garages. Combo units can satisfy both in one device.
Battery or hardwired alarms?+
Hardwired alarms (with battery backup) interconnect so all sound together and never need a battery swap to function, the standard in newer homes. Battery alarms are easy to add anywhere; choose 10-year sealed-battery models so you are not changing batteries yearly. Both work; many homes mix them.
Combo smoke and CO, or separate units?+
Combo smoke + CO alarms cover both hazards in one device, which is convenient and ensures CO coverage where you need it. Separate units let you place CO alarms exactly where appliances are and smoke alarms by sleeping areas. Combos are popular for simplicity; either approach works if coverage is complete.
Are smart smoke detectors worth it?+
If you want phone alerts when you are away, voice announcements of which room has an issue, and easy testing and silencing, yes. Smart alarms add real convenience and remote awareness, especially in larger homes. Basic alarms protect just as well in the room; smart adds notification and location features.
How often should I replace smoke and CO alarms?+
Replace smoke alarms about every 10 years and CO alarms about every 5 to 7 years (check the date on the unit), since the sensors degrade. Test them monthly, replace batteries yearly in non-sealed units, and replace the whole alarm when it chirps end-of-life or reaches its date.