Health & Wellness · Head-to-head
Kidde KN-COP-DP-10YL Worry-Free Plug-in CO Alarm vs First Alert CO710 Carbon Monoxide Alarm with 10-Year Battery
Which should you buy? Our verdict on both, pulled from our full The Best Carbon Monoxide Detectors: 4 Compared (and One to Skip) comparison.
The Kidde wins because it removes both failure modes at once: no battery to forget, and a display that survives a blackout when more than 100 ppm is present. The First Alert CO710 gets you the same 10 year sealed life and a clearer display for less, as long as a tabletop unit suits where you need it.
Kidde KN-COP-DP-10YL Worry-Free Plug-in CO Alarm
Buy itA plug-in alarm with a sealed 10 year lithium backup and an LED ppm readout, sold with the most complete published spec sheet in the category.
- Kidde's data sheet states an electrochemical fuel cell sensor, 85 dB at 10 feet, a 10 year limited warranty, and listing by UL to the UL 2034 standard.
- The sealed lithium backup keeps it running through a power cut and cannot be borrowed for the TV remote.
- A peak level button recalls the highest CO concentration recorded since the last reset, which Kidde notes is useful for medical responders.
- The display shows nothing until CO reaches 30 ppm, which is a UL 2034 rule rather than a Kidde choice, so a blank screen is not evidence of clean air.
- Kidde specifies display accuracy of plus or minus 30 percent, so read the number as a magnitude rather than a measurement.
- The display switches off when AC power is removed unless more than 100 ppm is detected or the unit is alarming.
First Alert CO710 Carbon Monoxide Alarm with 10-Year Battery
Buy itA sealed 10 year battery alarm with a backlit display that sits on a shelf, so there is nothing to wire, mount, or replace.
- First Alert lists it to the UL 2034 standard with an electrochemical sensor, a 10 year sealed lithium battery, and a 10 year limited warranty.
- The backlit display shows CO concentration in ppm, a recent peak level, and room temperature.
- First Alert says it needs no installation, which makes it the alarm a renter can put beside the bed on day one.
- First Alert positions it as a tabletop or shelf unit, so it is not the answer if you want something fixed high on a hallway wall.
- Like every UL 2034 alarm the display stays blank below 30 ppm, so it will not reveal a slow chronic leak.
- There is no interconnection, so an alarm in the basement will not wake anyone upstairs.
Side by side
| Kidde KN-COP-DP-10YL Worry-Free Plug-in CO Alarm | First Alert CO710 Carbon Monoxide Alarm with 10-Year Battery | |
|---|---|---|
| Our verdict | Buy | Buy |
| Best for | Someone who wants one alarm per level, permanently powered, that they never have to maintain or think about again. | Renters, dorm rooms, and anyone adding a bedside alarm without drilling into a wall. |
| Price tier | $$ · mid-range | $ · budget |
The bottom line
Our overall pick is the Kidde KN-COP-DP-10YL Worry-Free Plug-in CO Alarm - A plug-in alarm with a sealed 10 year lithium backup and an LED ppm readout, sold with the most complete published spec sheet in the category. Choose the First Alert CO710 Carbon Monoxide Alarm with 10-Year Battery instead if renters, dorm rooms, and anyone adding a bedside alarm without drilling into a wall.
Want the full picture, including the other options we compared and the popular one we'd skip? Read the complete The Best Carbon Monoxide Detectors: 4 Compared (and One to Skip).