How we picked
We don’t own these, we don’t run a lab, and we would not set fire to anything if we did. Nothing here is a test result. Every figure in the tables above was read from the manufacturer’s own published page on the date in the sources — ring.com and kidde.com — and where a maker doesn’t publish a number, the row says Not published instead of a guess. That is why several decibel figures are blank. Our Lease-Safe rating is editorial and derived from the published install method, and in this category we have applied it harder than usual rather than more generously, which is why two of the five picks are rated Limited.
Four criteria decided the order, in this priority:
1. Does it work without touching the landlord’s hardware? This is the entry requirement and it reorders the whole category. A product that replaces an existing alarm is not a renter product, however good it is, because the thing it replaces is not yours and its removal is the kind of thing that shows up on an inspection. Anything that adds to what is already there beats anything that swaps it out.
2. What does it actually need from you? An outlet is free. A tabletop is free. A hole in a ceiling is not, and neither is a hole in a ceiling you have to explain. We rank a device that plugs in above a device that mounts, and we say plainly which is which rather than describing a screw-mount alarm as “easy install.”
3. Does the alert reach you when you are not home? A local siren is the entire product in a house where somebody is usually in. In a studio that is empty ten hours a day it is half a product. Anything that pushes to a phone earns a large amount of credit here — but only if the pushing is included, not rented back to you monthly.
4. Is it still going to be sold and supported? This is a life-safety device you are meant to trust for the better part of a decade, so we checked availability at the manufacturer as well as the retailer. That check removed a genuinely cheap, genuinely in-stock alarm from this page — details in the section on what we didn’t pick.
One thing worth saying up front, because a reader will notice it: three of the five picks are Kidde. That is not a relationship, it is the shape of the American market — consumer CO alarms here are essentially Kidde and First Alert, and on the day we wrote this the First Alert models that fit a renter were either discontinued by First Alert or had no live in-stock offer. We would rather tell you that than pad the list with a fifth brand for the look of the thing.
The rule that decides everything: the alarm up there isn’t yours
In most of the country your landlord has a legal duty to provide working smoke alarms and to keep them working, and the exact rules — how many, where, who replaces the batteries, what you have to report and how quickly — are set state by state. Our apartment law explainer makes the same point about cameras: there is no national answer, only your state’s answer, and the Nolo directory in the sources below is the fastest way to find it.
What is consistent enough to state flatly is the other direction. Removing an alarm, taking the battery out to stop it chirping, or bagging it because the stove sets it off is a bad idea in every state: it is very commonly a lease violation, it is frequently a fire-code violation, and if there is ever a fire it is the single worst fact that can exist about your tenancy. If your landlord’s alarm is broken, chirping, or older than ten years, the move is a written maintenance request, not a screwdriver. Put it in writing precisely because it is the kind of request that creates an obligation.
Everything on this page is designed around that constraint. The top pick works because it does not touch the landlord’s alarm — Ring is explicit that the device “does not detect fire, smoke or carbon monoxide” and instead listens for one that does. You are not upgrading the alarm. You are giving it a phone.
Carbon monoxide is the gap, not smoke
Here is the part most renters have backwards. You are extremely likely to have a smoke alarm, because somebody was legally required to give you one. You are much less likely to have a carbon monoxide alarm, because CO requirements vary far more by state and by building age, and because nothing about a missing CO alarm is visible. There is no smell. There is no smoke. The U.S. Fire Administration calls it the invisible killer for exactly that reason.
Whether you need one is a question about your appliances, not your building. Carbon monoxide comes from things that burn fuel: a gas range, a gas oven, a gas furnace or boiler, a gas water heater, a fireplace, a wall heater, or a car or generator running in an attached or underneath garage. USFA puts it as a device or appliance “not working or vented properly.” If your unit is all electric, has no attached garage, and has nothing gas-fired anywhere in the building envelope, your CO risk is genuinely low. If any one of those is true — and in older housing stock, gas ranges are extremely common — a CO alarm is the highest-value thing on this page.
The renter-friendly part is that CO behaves differently from smoke. Smoke rises, which is why smoke alarms live on ceilings and why they are a mounting problem. Kidde publishes the counterpoint on its own product page: carbon monoxide “evenly disperses in the air,” so a CO detector “can be installed anywhere on the wall.” That is why the plug-in CO alarm exists, and why it is the rare life-safety device that a renter can deploy in ten seconds with zero consequences. USFA’s placement guidance is to install CO alarms in a central location outside each separate sleeping area and on every level of the home — in a one-bedroom, that is usually one alarm in the hallway outlet.
Where all of this actually goes in a small apartment
Take five minutes and walk the unit before you order anything.
Find every alarm that already exists and read the date on it. Twist it off its base — that is allowed, and you do not need a tool — and look for a manufacture date printed on the back. USFA is unambiguous that the whole alarm gets replaced ten years from that date, and Ring will not support a listener next to a detector older than that, so this one number decides whether the top pick on this page is even an option for you. If the date is missing or past, that is your maintenance request, and it is a request with a federal agency’s guidance behind it.
Note which rooms have nothing. USFA’s guidance is alarms inside and outside each bedroom and sleeping area, and on every level. Rentals miss this constantly: a converted den used as a bedroom, a basement apartment’s second room, a long hallway where the only alarm is at the wrong end. Those rooms are the case for adding an alarm of your own, and the case where you have to decide whether two small holes in a ceiling are worth it. Our view is that they are, and that spackle costs less than most things you have bought this month.
Find a hallway outlet for the CO alarm. Central, outside the sleeping area, not behind furniture, not right beside the stove, and not in a bathroom. A plug-in unit goes where the sockets are, which is the one real compromise of the format — if your only central outlet is behind a couch, the battery-powered CO alarm on this page is the better answer, because you can stand it on a shelf instead.
Test everything monthly. USFA says monthly, and it means the landlord’s alarms too — testing one is not tampering with it, it is pressing the button it has for that purpose. If it does not sound, that is a maintenance request the same day. While you are on a chair anyway, this is a good moment to think about the other silent apartment disaster, which costs a deposit rather than a life but is far more likely to happen to you.
The chirping problem, which is why people do the wrong thing
Search anything about smoke alarms and apartments and half the results are people asking how to make one stop. It deserves its own heading because the chirp is what makes otherwise sensible people pull a life-safety device off a ceiling at midnight.
A single chirp every thirty to sixty seconds is almost always a low battery, and USFA’s guidance is to replace the batteries at least once a year in the models that take them. In a rental, whose job that is depends on your state and your lease, and it is worth knowing the answer before it happens at 3am rather than after. If the alarm has a sealed ten-year battery, there is no battery to change: the chirp means the alarm has reached end of life and the whole unit needs replacing, which is your landlord’s job on your landlord’s alarm.
A full alarm every time you cook is a different problem with a different fix, and the fix is not the alarm’s battery. USFA’s suggestion for nuisance alarms is to move the whole alarm several feet further from the kitchen or bathroom — which, in a rental, is again a conversation rather than a job. What you can do yourself is reduce what reaches it: use the range hood or a window fan, keep the oven clean, and shut the kitchen door if there is one. Two of the alarms on this page publish reduced cooking nuisance alarms as a feature, which matters disproportionately in the kind of apartment where the kitchen is a wall of the living room.
What we didn’t pick, and why
The cheap 10-year combination alarm that’s all over Amazon. First Alert’s SMCO210 is a slim, sealed-battery smoke and CO alarm at a good price and it is genuinely in stock. We left it off because First Alert’s own product page for it says the product “is no longer available for sale” and labels it discontinued. Remaining retail stock is real, but you are being asked to trust this device for a decade, and a decade is a long time to own something the manufacturer has already exited.
Nest Protect, and its successor. Google stopped making the Nest Protect in March 2025 and now points buyers at First Alert’s SC5 smart alarm instead. The SC5 is the closest thing to a direct replacement, but the battery-powered version returned no live in-stock offer when we checked, and at its published price it costs about five times the listener that solves most of a renter’s problem. If you already own Nest Protects, they keep working — Google has said existing units continue to get updates.
Hardwired and interconnected alarms. The correct product for a whole house and completely off the table here. They connect to a wiring harness in the ceiling, which means the alarm on that harness is the landlord’s installation, not a slot for your upgrade. If your unit has hardwired alarms, your entire contribution to this category is the listener and the CO alarm.
Magnetic “no-drill” smoke alarm mounting kits. There is a whole shelf of these from brands with no website, promising you can stick an alarm to a ceiling with adhesive and a magnet. We are not recommending one. Every spec on this site has to trace back to a manufacturer that publishes something, and more to the point, a ceiling is the hardest place adhesive has to work — gravity pulls straight down on the bond all day, every day. Our adhesive mounting guide covers where sticking things up is a great idea. A fire alarm is where we stop.
Anything that only makes noise where nobody is. This is the same editorial line we took on leak sensors. A device whose entire output is sound in an empty room has not solved the problem you are buying it to solve; it has solved a problem your neighbors have. That is why the listener ranks first and why the standalone alarm ranks last, even though the standalone alarm is the one that actually detects things.
What to buy, in order
If you rent and you buy one thing from this page, buy the listener. It is the cheapest item here, it converts an alarm you are not allowed to modify into one that reaches you at work, and its only real cost is that it wants to sit within a few inches of the existing alarm. Check the date on that alarm first: Ring requires the detector it listens to be ten years old or less.
If anything in your building burns fuel — a gas range counts, an attached garage counts — buy a CO alarm second, and buy the plug-in one if you have a central outlet. Nothing else on this site delivers this much protection for this little install. If your only outlet is in the wrong place, or you are in a dorm where you may not fix anything to anything, the battery version stands on a shelf and does the same job without the app.
Buy an alarm of your own only for a room that genuinely has none. If that room exists, decide between the smart one and the value one on a single question: will anyone be home to hear it? If the answer is often no, pay for the one that pushes to your phone and interconnects with a second unit. If the answer is usually yes, the cheap sealed-battery combination alarm is not a compromise, it is just the right amount of product.
And when you move, all of it comes with you. The listener unclips, the plug-in CO alarm goes in a drawer, and the alarm you mounted comes down with a screwdriver and leaves two holes a tub of filler will close in a minute. That is worth putting on the moving-out checklist with everything else, because a smoke alarm you paid for is exactly the sort of thing people leave on a ceiling by accident. If you are still building the rest of the setup, our no-contract apartment alarm roundup covers the intrusion half of the same problem, and renter-friendly upgrades ranks everything on this site by how cleanly it comes back off.
