Best Budget Carbon Monoxide Detector (2026): 5 Cheap CO Alarms

GadgetRoost is reader-supported. As an Amazon Associate we earn from qualifying purchases. This does not change our recommendations. Learn more.

The best budget carbon monoxide detector keeps costs low so you can put an alarm near every sleeping area without cutting corners on the basics.

We compared 5 cheap CO alarms by power source and essential features.

Quick Answer: The Best Budget Carbon Monoxide Detector

• Best Budget Overall: First Alert Battery Carbon Monoxide Alarm CO400
• Best Budget Runner-Up: Kidde Carbon Monoxide Detector, AA Battery Powered CO Alarm with LEDs
• Best Budget Multi-Pack: First Alert Plug in Carbon Monoxide Alarm CO606, 3-Pack
• Best Budget Portable: Kidde Carbon Monoxide Detector, AA Battery Powered, Portable for Travel or Home, 3rd Edition
• Best Budget Plug-In: First Alert Plug in Carbon Monoxide Alarm CO606, 9V Battery Backup

The First Alert CO400 Battery CO Alarm is our best budget carbon monoxide detector. The Kidde Battery CO Detector (AA) is a close second, and the First Alert CO606 3-Pack covers three rooms.

Best Budget Carbon Monoxide Detector Comparison Table

The 5 Best Budget Carbon Monoxide Detectors

Each pick below was compared on sensor type, power source, alerts, certification and value.

Best Budget Overall

First Alert Battery Carbon Monoxide Alarm CO400

9.0/10 GR Score ⓘ

Check Price on Amazon.com ↗

1The First Alert CO400 is a battery-powered CO alarm with an electrochemical sensor and an 85 dB siren.

👍 Pros & Cons

Pros

• Battery-powered, works in outages
• End-of-life chirp
• 5-year limited warranty

Cons

• No digital readout

📄 Detailed Review

• Type: Battery CO alarm
• Includes: Alarm + batteries
• Key feature: Electrochemical sensor, 85 dB

An end-of-life chirp tells you when to replace it, and it carries a 5-year limited warranty.

It is a budget favorite.

Check First Alert CO400 Battery CO Alarm Price on Amazon

Best Budget Runner-Up

Kidde Carbon Monoxide Detector, AA Battery Powered CO Alarm with LEDs

8.8/10 GR Score ⓘ

Check Price on Amazon.com ↗

2This Kidde CO alarm runs on two AA batteries, so it works anywhere and during power failures.

👍 Pros & Cons

Pros

• No wiring or outlet needed
• Peak Level Memory
• Wall or tabletop

Cons

• Batteries need changing

📄 Detailed Review

• Type: Battery CO alarm
• Includes: Alarm + 2 AA batteries
• Key feature: 2-AA batteries, LEDs, peak level memory

It uses an electrochemical sensor, an 85 dB alarm and Peak Level Memory.

It is a flexible, low-cost choice.

Check Kidde Battery CO Detector (AA) Price on Amazon

Best Budget Multi-Pack

First Alert Plug in Carbon Monoxide Alarm CO606, 3-Pack

8.8/10 GR Score ⓘ

Check Price on Amazon.com ↗

3This 3-pack of First Alert plug-in alarms covers several bedrooms or floors at once.

👍 Pros & Cons

Pros

• Three alarms for several rooms
• Battery backup
• 7-year limited warranty

Cons

• No digital readout

📄 Detailed Review

• Type: Plug-in CO alarms
• Includes: 3 alarms
• Key feature: Three alarms, battery backup

Each alarm has battery backup and a single test/silence button.

It is the easy way to cover a whole home.

Check First Alert CO606 3-Pack Price on Amazon

Best Budget Portable

Kidde Carbon Monoxide Detector, AA Battery Powered, Portable for Travel or Home, 3rd Edition

8.4/10 GR Score ⓘ

Check Price on Amazon.com ↗

4Kidde’s portable CO alarm runs on two AA batteries and can sit on a tabletop or hang on a wall.

👍 Pros & Cons

Pros

• Portable for travel
• Mount on a wall or set on a table
• Event Memory

Cons

• Batteries need changing

📄 Detailed Review

• Type: Portable battery CO alarm
• Includes: Alarm + 2 AA batteries
• Key feature: 2-AA batteries, event memory

It is light enough to pack for a rental or cabin.

It is a smart second alarm for travel.

Check Kidde Portable CO Detector Price on Amazon

Best Budget Plug-In

First Alert Plug in Carbon Monoxide Alarm CO606, 9V Battery Backup

8.6/10 GR Score ⓘ

Check Price on Amazon.com ↗

5The First Alert CO606 plugs into any standard outlet and keeps a 9V battery for backup.

👍 Pros & Cons

Pros

• Plug-in with battery backup
• Low-battery signal mute
• 7-year limited warranty

Cons

• No digital readout

📄 Detailed Review

• Type: Plug-in CO alarm
• Includes: Alarm + 9V battery
• Key feature: Plug-in, 9V backup, single button

A single test/silence button runs the tests, and a low-battery mute quiets chirps for up to 8 hours.

It is a simple plug-in pick.

Check First Alert CO606 Plug-In CO Alarm Price on Amazon

How We Chose the Best Budget Carbon Monoxide Detector

To choose the best budget carbon monoxide detector, we compared popular CO alarms and smoke-and-CO combos on Amazon by power source, display, alerts, listed standards and owner feedback.

CDC advises installing battery-operated or battery back-up CO detectors near every sleeping area; see the CDC carbon monoxide poisoning basics.

Product details in this guide are based on manufacturer specifications and verified owner feedback. Read more on our How We Test page.

Buying Guide: Cheap but Safe

Keep these points in mind before you buy.

Look for UL 2034

Home CO alarms in the US are tested to UL 2034. Combo alarms also list UL 217 for smoke.

Skip the extras

Displays and apps are nice, but a listed sensor, a loud alarm and backup power are what matter most.

Test and check batteries

Press the test button monthly, and check batteries when you change the clocks each spring and fall, as CDC recommends.

Budget Tips

Stay safe for less:

• One per sleeping area.
• Test monthly.
• Check batteries at clock changes.
• Replace on schedule.

Quick answers about the best budget carbon monoxide detector.

Frequently Asked Questions

What is the best budget carbon monoxide detector?

The best budget carbon monoxide detector is the First Alert CO400, with Kidde’s AA model as the runner-up.

What is the cheapest safe CO alarm?

A UL 2034-tested battery alarm from a known brand.

Do budget alarms have displays?

Usually not; a display is optional.

How long do budget alarms last?

Follow the maker; CDC says every 5 years or per instructions.

Can I move a battery alarm?

Yes, but keep one near every sleeping area.

Final Verdict

Our final pick for the best budget carbon monoxide detector is the First Alert CO400 Battery CO Alarm. Choose the Kidde Battery CO Detector (AA) if you want a close second, or the First Alert CO606 3-Pack to cover three rooms.

Related Guides

More home safety guides:

• Best Carbon Monoxide Detector
• Best Affordable Carbon Monoxide Detector
• Best Alternative to Carbon Monoxide Detector
• Best Emergency Power Supply for Home
• Best Air Purifier for Bedroom

Product details are based on manufacturer specifications at the time of writing. Prices and availability change often, so check Amazon for the latest price.