The Best Mug Warmers

When the Ember Mug first hit the scene—at the height of the let’s-make-everything-“smart” craze—it took a lot of, er, heat in the press. A coffee mug with a battery that you have to control with your phone? With to-the-degree temp control? Really?

But it turned out that owners truly liked the thing—as does noted coffee guru James Hoffmann. And since then it has caught on to the extent that even Costco stocked it at one point.

The Ember Mug 2 has remained on this list since we first tested mug warmers in 2021, even though the price tag still makes us cringe.

It keeps your drink at a consistent temperature. For around $150, it had better. But during our testing we were impressed to find that it kept our beverage within 1 Fahrenheit degree, plus or minus, from the set temperature. If you want to maintain the optimal drinking temperature for your coffee, the Ember Mug 2 allows you to get it right down to the degree.

“I think maintaining drinking temp, rather than serving temp, is the way to go,” said Hoffmann. “Thermoses work well but tend to hold the coffee hotter. I haven’t tried anything else comparable to the Ember.” In a blind taste test, Hoffmann even found that keeping coffee hot with the Ember Mug yielded less harshness and bitterness than other, traditional methods of reheating.

In a previous round of testing, we found that it maintained its temperature even through a brisk dog walk in 40 °F weather. It was also one of the few mugs that could warm a room-temperature drink up to the ideal drinking temp, in about 20 minutes.

It has the longest battery life of any self-heating mug we tested. Clocking in at 2 hours, the Ember Mug 2’s battery life was much longer than that of the Nextmug (just over 1 hour 30 minutes) and the Thermacup (around 1 hour 20 minutes).

Lids for the Ember Mug 2 are sold separately, for about $15, but they may be worth the expense since they help insulate your drink while the mug is running, and they also keep it warmer for longer after the battery has been fully depleted. (This is, of course, the case for all mugs, smart or not, and a plate over a ceramic mug achieves the same effect.)

It has plenty of volume. Battery-in-the-bottom mugs all have the same flaw: The battery takes up significant drink space in the cup. It’s almost like a false-bottom drawer—the mug looks deeper from the outside than it is on the inside. The Ember Mug 2 was the least offensive of the bunch in this regard, with a volume that seemed to come closest to matching the mug’s visual appearance.

That said, we tested the 14-ounce mug, not the 10-ounce version. Since 14 ounces is about the size of a normal mug, we suspect that the capacity helps alleviate the feeling of coming up short on your drink. With the 10-ounce mug, you might feel shortchanged.

It looks good and feels fancy. Some of the mug warmers we tested were real uggos. Though we wouldn't go so far to say that this mug is cute, the metallic edition of the Ember Mug 2 that we tested looked sleek on desks and end tables, and the charging dock was unobtrusive, just big enough to hold the mug.

The Ember Mug 2 comes in mostly neutral shades that blend in nicely with any decor, though there are some standouts, including candy-apple red. Ember also drops new shades from time to time; powder blue and lavender are new additions at this writing.

Drinking from the Ember Mug 2 feels a little luxurious, too. Maybe there’s a bit of confirmation bias going on because of the steep price tag, but we found it weighty and well balanced, and the handle is a comfortable size.

The app allows for exact temperature settings. The Ember Mug 2 pairs to your smartphone via Bluetooth, and its app makes changing the temperature of your drink as easy as sliding left or right on the main screen. Pairing our phone was easy and took only a minute (if that).

The app makes it very clear when the mug is turned off, displaying a gray screen instead of its usual yellow-to-red range of hues. If you try to set the temperature with the mug off or empty, the slider snaps back to “off” after a few seconds.

The app has preset temperatures for common drinks such as lattes, drip coffee, black and green tea, and cappuccinos. You can also save custom presets anywhere between 120 °F and 145 °F. It has a tea timer, which is nice for people (like me) who forget they have tea steeping and ultimately over-steep. And at the very bottom of a secondary menu, there’s even a card with a handful of recipes. When your phone’s battery is dead, or you’ve turned it off, you can still use the Ember Mug 2 —it just defaults to 135 °F.

We’ve seen reviews detailing issues with the latest version of the Android app, including from some owners who say that they have to continually re-pair their mug with the app or are unable to make custom presets. Our Android tester (who uses a Google Pixel 9 Pro) did not encounter any of those issues, but we did have to factory-reset the mug before it would pair with her phone.

It has commonsense safety features. When the Ember Mug 2 is empty, it does not heat up. You can run the slider up and down all you want, but the mug stays in “sleep mode” until you add liquid.

After standing two hours untouched, the mug shuts off, even if liquid remains and even if the mug is docked. Other battery-powered mugs didn’t shut off at all as long as they were docked, slowly causing my tea to evaporate and leaving a sticky tea syrup that was very disconcerting.

Flaws but not dealbreakers

• It costs a lot more than most mug warmers. No matter how “smart” the Ember Mug 2 is and how well it works, at the end of the day, a $150 mug is kind of ridiculous. For the right person, it could be money well spent to keep expensive coffee at just the right temperature for as long as possible. Regardless, the Ember Mug 2’s price tag is a stiff barrier to entry. It strikes us as a good gift; you might not buy it for yourself but would be happy if you got it as a present.
• You can’t run it through the dishwasher or put it in the microwave. Because of the open connections on its base, putting the Ember Mug 2 in the dishwasher is likely to destroy it. Some owners report that the mug worked fine after a trip through the dishwasher, but we don’t recommend trying that. The Ember Mug 2 is easy to wash by hand, and most of the time you can probably just give it a good rinse and be fine.

Specs:

• Capacity: 14 fluid ounces, 10 fluid ounces
• Safety shutoff: after two hours without movement or if the mug is empty
• Wash instructions: hand-wash only

For some people, the idea of needing an app to control the exact temperature of your mug is, well, a little much. If you want a “dumb” battery-powered mug, Nextboom’s Nextmug is a lower-tech option that keeps tea warm with the touch of a button. You have three levels to choose from: warm (130 °F), hot (140 °F), and piping (150 °F).

It’s roomy and cute. Like the Ember Mug 2, the Nextmug has a 14-fluid-ounce capacity, so it seems spacious even with a battery taking up space in the bottom. And whereas the Ember Mug 2 goes tall, the Nextmug goes wide, with a rather charming short-and-squat appearance.

It’s easy to operate. The Nextmug has no app. In fact, it sports only a single button and a row of lights that indicate what your mug is up to.

Simply press to turn it on, keep pressing to set your desired temperature, and press again to turn it off. The lights at the bottom indicate whether your drink has reached your desired temperature. That’s it: No app, no muss, no fuss.

The button can be slightly tricky to reach. It’s at the bottom of the mug, so you need a steady hand to adjust the mug’s temperature when it’s full of liquid. That said, the safety shutoff gives you a 60-second window before the mug shuts off in the absence of liquid, so if holding a hot drink over your head poses a problem, you can simply set your ideal temp before you fill it up.

It maintains a rock-steady temperature. In fact, the Nextmug was one of two warmers that perfectly maintained their temperature until the battery ran out (the other was the Mr. Coffee Mug Warmer). Even the more-expensive Ember Mug 2 varied by ±1 degree from its set temperature.

Flaws but not dealbreakers

• The battery life is only okay. Off the dock, the Nextmug lasted only an hour and a half. That’s fine if you’re working at your desk and set the mug on the dock between sips, but that might not be long enough if you’re lounging on the couch watching TV. Unlike the Ember Mug 2, the Nextmug comes with a lid that keeps your drink warm a little longer once the battery has died, but it’s no replacement for more battery capacity.
• This mug is also expensive. At $130, the Nextmug is only slightly cheaper than the Ember Mug 2, and it doesn’t offer an app or precise temperature control to justify the price. That’s pretty steep, particularly when the $20 Mr. Coffee Mug Warmer produced the exact same results in our temperature-control test. Like the Ember Mug 2, this mug is worth the investment only if you think you will benefit from a mug that can heat itself away from a dock or hot plate.

Specs:

• Capacity: 14 fluid ounces
• Safety shutoff: after 60 seconds with no liquid or after two hours with no movement
• Wash instructions: hand-wash only

The Ohom Ui 2 Self-Heating Ceramic Mug is the one for the Instagram girlies. It’s short and cute, and it has a sleek base that doubles as a wireless phone charger. It looks stunning on a desk, but without a battery in the bottom, it needs to return to its base to stay at ideal drinking temperature.

This combo lies somewhere between a hot plate and a battery-powered mug. The base accepts only this mug—other ceramic mugs don’t heat up when placed on the charging pad. The base of the mug is filled with metallic particles, which react with a magnet in the pad to enable induction heating.

It’s one of the best-looking mugs we’ve tested. The design is elegant, which can’t be said about most other mug warmers. At best, its rivals, such as the Ember Mug 2 and the Nextmug, are sleek and understated, or at least not offensive to look at. But the Ohom mug is legitimately cute, with a distinctive shape and a gracefully curved handle. It also comes in a few different colors, so you can match it to your desk decor.

The base is also a phone charger. The induction technology that heats the Ohom mug can also wirelessly charge Qi-compatible devices, such as smartphones, so the pad doubles as a charger.

A small desk might benefit from a setup like this since it reduces two devices to one. And though this base isn’t certified by the Wireless Power Consortium (which oversees Qi wireless charging standards), our testing indicated that Ohom’s advertised 7.5-watt iPhone charging rate is accurate.

The mug doesn’t have to stay docked. No battery means no docking, so you can store the Ohom mug with the rest of your mugs and pull it out when you’re ready to use it, instead of keeping it permanently on your desk. It’s a small thing, but it’s nice to be able to snag the Ohom mug from the cabinet like any other mug when you’re making a cup of tea or coffee.

Flaws but not dealbreakers

• It can’t stay hot away from its pad. One of the main perks of self-powered mugs like the Ember Mug 2 and the Nextmug is that, well, they heat themselves. They stay warm when you’re moving around, so you can take one on walks on a cold day, on your commute (though you’ll want a lid for that), or just around the house. Because the Ohom mug has to be in contact with its plate to keep warm, it’s less versatile.
• The mug and the warmer get hot. And I mean wicked hot. The first time I grabbed the mug by its body rather than its handle, I instinctively yanked my hand away. For me, the mug was almost too hot to handle, but my partner handled it with no reaction, holding it by the bottom of the mug in his bare hand. As for the charging pad, although you can charge your phone on it right after the mug has been on it, that isn’t something I recommend doing. The charger, like the mug, was hot enough that I was worried my phone would overheat.

Specs:

• Capacity: 11 fluid ounces
• Safety shutoff: after an hour of no use
• Wash instructions: mug is dishwasher-safe

I was so ready to dislike the Mr. Coffee Mug Warmer. It’s clunky and ugly. It’s the secret-Santa gift you might get a co-worker you don’t like. But appearances can be deceiving. This basic mug warmer blew me away with its reliability, producing the best results in our temperature-regulation test.

And even better, it costs only $20.

It keeps the same temperature for as long as you want. The Mr. Coffee warmer kept my tea at precisely 129 °F from the time it hit the correct temperature to when I finally turned it off. The only other mug warmer that performed equally well in our tests was the Nextmug, but that mug can sustain the temperature for only an hour and a half.

It’s blessedly simple. Pour drink. Turn on warmer. Put mug on warmer. Done.

The Mr. Coffee warmer has no buttons, no apps, nothing but one little switch and an indicator light. It’s about as simple as you can get—really nothing more than a very small hot plate.

You can actually turn it off. Most of the other hot-plate-style mug warmers we tested, such as the Bestinkits warmer (a former pick), are weight-activated. The manufacturers use fancy marketing terms like “gravity sensors,” but basically you put a mug (or any other object) on the warmer, and it starts heating up.

The Mr. Coffee warmer has a simple on/off switch, so when you turn it off, it stays off. The catch is that you have to remember to turn it off when you walk away—which I, admittedly, forgot to do more than a few times during testing.

You can use your own mugs. All of the other warmers on this list require you to use a specific mug, but the Mr. Coffee warmer works with any mug you already have, provided it fits. Some of my larger mugs didn’t, but every standard-size mug fit wonderfully.

Flaws but not dealbreakers

• Depending on your taste, 129 °F might be a little low. During testing, there were moments when my drink felt lukewarm. If you need a piping-hot drink, the Ember Mug 2 can reach 145 °F, and the Nextmug’s hottest setting, aptly labeled “piping,” hits 150 °F.
• It’s ugly. There’s no sugarcoating it—the Mr. Coffee warmer doesn’t look good. It reminds us of a coffee warmer we might find at a diner. But if you don’t mind the looks, it’s a rock-solid option.

I’m an updates writer and a member of Wirecutter’s kitchen team, and I have covered ice cream scoops, graters, salad spinners, and more. Previously, I worked at Good Housekeeping, testing products and writing reviews. Much to my partner’s chagrin, I have multiple shelves in my kitchen dedicated to tea and coffee.

For this guide:

• I researched different mug warmers to arrive at the nine finalists we tested for our 2024 update, sifting through product reviews, blog posts, and content from coffee experts.
• I spent days pouring, drinking, and checking the temperature of cups of tea and coffee, putting each warmer through multiple workdays of use.
• Associate staff writer Haley Perry, who conducted previous rounds of testing for this guide, also covers alcoholic beverages and video games for Wirecutter. She has been working professionally as a bartender since the day after she turned 21, and she has served as a spirits-competition judge, writer, and consultant.
• Like all Wirecutter journalists, I review and test products with complete editorial independence. I’m never made aware of any business implications of my editorial recommendations. Read more about our editorial standards.

For such a niche product, there are a lot of mug-warming devices for sale. They fall into three categories: mugs with batteries, mugs without batteries, and hot plates.

Mugs with batteries usually come with a wireless charging base where they sit when they’re not in use, and they can heat liquid and maintain its temperature when you use them away from the base. Most of these mugs provide some way for you to adjust the temperature, whether it’s degree-specific as with the Ember Mug 2 or via preset temperatures as with the Nextmug. Battery life varies, but all of the self-heating mugs we tested lasted for at least an hour away from their bases. These mugs are usually not dishwasher-safe because of open connections at the bottom of the mug.

Mugs without batteries but with a base can’t heat liquid or maintain the temperature on their own but come with a dedicated hot-plate base that keeps the mug warm. These models vary in ability—some maintain only one set temperature, while others allow you to set them to the degree. Since the mugs have no battery at the bottom, they’re often dishwasher-safe, though this varies from model to model.

Hot plates are barebones conductive heating elements that can warm most, if not all, mugs, though some advise against them using with glass. They can be turned off or on, or are activated when they sense weight. They offer only one set temperature.

No matter how fancy or plain, all of the mug heaters we evaluated had to meet the same criteria:

• Ease of use: We dismissed any mug warmers with unclear instructions, poor design, or difficult controls. Using a mug warmer should be a relaxing experience, and there’s nothing relaxing about endlessly fussing with your warmer just to get it to work.
• Safety shutoff: All of our recommendations have some sort of safety shutoff or allow you to turn them off without unplugging them. They might function at relatively low temperatures, but mug warmers are hot plates, so they still pose a fire risk if you leave them on and unattended (as some of the comments on an earlier version of this guide can attest to). If a mug warmer could be accidentally turned on without the user’s knowledge, we gave it the boot.
• Temperature control: We looked for mug warmers that could maintain a steady temperature without too much fluctuation. When applicable, we also tested the mug warmers’ internal thermometers for accuracy to confirm that the set temperature matched the temperature of the liquid inside the cup.

I put each mug through at least a full workday of use as I worked from home, and I noted whether I had to interrupt my workflow to mess with each warmer to get it to work. I also kept track of how long each model took to charge and whether the advertised safety shutoff features functioned as described.

To test each mug warmer’s temperature control, I lined all nine contenders up in my tiny New York City apartment (my partner was appalled), filled them with boiling water fresh from the kettle, and took their temperature with the same thermometer every 10 minutes for two hours or until the battery died.

I kept mugs with batteries off their docks to confirm that they were operating solely on battery power. I set any warmers with the ability to adjust the temperature as close to 130 °F as the presets allowed.

If you want a self-heating mug that’s fully kitted out: The Ikago Heat Coaster Pro Set comes with the most accessories, including a lid and a dedicated spoon. It looks pretty slick, too, with all-black components. The touchscreen is easy to operate despite its small size, and along with the Ember Mug 2, the Ikago model was the only other mug we tested that could bring room-temperature water up to a drinking temperature.

Our main gripe is that while the temperature did stay generally consistent in our tests—between 151 °F and 154 °F—the temperature of the drink was always hotter than the temperature indicated on the screen, at some points by up to 4 degrees. But if you want a dedicated coffee and tea setup, this Ikago set offers all the bells and whistles at less than half the price of the Ember Mug 2 at this writing.

This is not a comprehensive list of all mug warmers and self-heating mugs we’ve tested. We have removed any models that are no longer available or do not meet our criteria.

Mugs with batteries

At just at $40, the Thermacup Self-Heating Temperature-Controlled Mug is impressively cheap for a mug with a battery in the bottom. Every other battery-powered mug we tested cost at least $100.

Unfortunately, its temperature control was abysmal; my tea dropped 12 degrees in 10 minutes and rocketed back up 7 degrees over the next 10 minutes. This mug also has no apparent safety shutoff; I forgot about it on my desk and returned a few hours later to syrupy tea that would have kept reducing until all the water evaporated.

Using the Glowstone Smart Mug was an exercise in patience—which is a shame, as it’s made of gorgeous bone china. The instructions were confoundingly vague and failed to address most questions the average person might have about the mug’s general operation.

For example, when discussing how to know when the mug needs charging, the instructions say “over time, you will learn the brightness levels to look for”—not that the battery level even mattered, since it died in under an hour. This mug reminded me of a DJ I once dated: very pretty, but entirely too complicated.

Mugs without batteries

The Cosori Coffee Warmer and Mug Set was easily the most annoying mug warmer I tested. Instead of letting you set a desired drinking temperature—you know, for the liquid in the mug—this Cosori set measures the temperature of the hot plate.

In practice, this involves setting the hot plate for 230 °F and hoping that your drink settles in around 150 °F. The instructions provide zero guidance as to where to set the hot plate temperature to get your desired beverage temperature, so you’re on your own. Plus, the materials felt downright junky, with a cheapo plastic lid and a flimsy mug.

Hot plates

The Bestinnkits Smart Coffee Warmer, a former pick, is unfortunately a fire hazard. Commenters let us know that this warmer can turn on without the user’s knowledge and potentially start a fire, and we were able to confirm this behavior in a new round of testing.

Since the warmer is activated by weight, any sufficiently heavy object falling onto it can turn it on, and because it has no on/off switch, the only way to eliminate this risk is to unplug it between uses.

This article was edited by Ben Keough and Erica Ogg.