ThermoWorks Thermapen One review

Check the temperature of your food in just one second

The ThermoWorks Thermapen One open and with the display in portrait mode on a balck granite chopping board
(Image: © TechRadar)

TechRadar Verdict

The ThermoWorks Thermapen One is an expensive but extremely accurate food thermometer. Compact and lightweight, it features an easy-to-read backlit display that rotates depending upon the way the thermometer is held, and it will even automatically switch off if it senses it isn’t being used.


  • +

    Provides a temperature reading in one second

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    Rotating backlit display

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    Compact design


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    Customization is fiddly

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One-minute review

Overcooked food can be dry and chewy, ruining an otherwise good meal. However, determining exactly how long to cook meat to the point that it remains juicy and succulent can be a struggle for many home cooks. This is where a meat thermometer can be a lifesaver, enabling you to check the internal temperature of food, so you know when it’s cooked. 

ThermoWorks’ Thermapen is widely considered one of the best food thermometers on the market, and it’s favored by professional chefs as well as home cooks. The brand’s latest model – the Thermapen One – is its most advanced yet. 

The Thermapen One has a built-in accelerometer that can identify the position in which the thermometer is being held, rotating the display accordingly, so it's easy to read the temperature without having to tilt your head at an angle. The display is backlit, too, so it can be clearly seen in all lights.

Sporting the same compact design as previous Thermapen models, the Thermapen One comprises a stainless steel food probe that folds back 180 degrees into the side of the gadget when it's not being used. However, where it differs is that it now takes just one second to deliver a temperature reading compared to the two to three seconds of previous models of Thermapen.

The Thermapen One is an expensive food thermometer, but for those who worry about how long to cook food to ensure it’s safe to eat but still succulent, it’s worth the investment – and it’s great for cooking steak to perfection, too. As well as checking the temperature of meat or meals that have been reheated, the Thermapen One will also prove handy for bakers when making sweet treats such as fudge, swiss meringue buttercream, or even when tempering chocolate. 

ThermoWorks Thermapen One price and availability

  •  List price: $105 / £66

The ThermoWorks Thermapen One will set you back $105 / £66 and comes in 10 colors including red, blue, black and purple. It’s available from ThermoWorks in the US, and the Thermapen website and Amazon in the UK.

ThermoWorks also offers the Thermapen Classic. This slightly more affordable meat thermometer doesn’t have a rotating display and takes around three seconds to register the temperature of food. It’s priced at $83 / £51.60.

The ThermoWorks Thermapen One being used to test the temperature of Chicken

(Image credit: TechRadar)


  • Rotating display
  • Backlight ensures it’s easy to read in all light
  • Food probe folds into the side of the thermometer

The ThermoWorks Thermapen One is a super-compact food thermometer. Measuring 6.1 x 1.7 x 0.74 inches / 0.82 x 15.62 x 1.93cm (w x h x d) and weighing just 0.25lbs / 115g, it can easily be slipped in a drawer – or even a bag, if you’re planning to cook on a weekend away. The stainless steel probe folds back through 180 degrees into the side of the plastic body of the thermometer for neat storage when it isn’t in use.

The thermometer is available in 10 colors including red, purple, and blue, and has a 1.54 x 1in / 1.43 x 1.185cm (w x h) LCD screen that shows the temperature reading. The LCD automatically rotates based on the position in which the thermometer is being held, so no matter the angle from which you look at it, the reading will always be displayed the right way up.

The display is backlit, too, and if the sensor on the front of the thermometer detects it’s a low light situation, it will illuminate the panel to make it easier to read. An IP67 rating means the thermometer will survive being submerged for a short length of time – but this isn’t recommended. 

Temperature range covers -58 to 572ºF / -49.9 to 299.9ºC, and can be customized to display in the unit of temperature you prefer. The thermometer also comes with a five-year warranty and has a new easy-to-access battery compartment, which is secured with only one screw. 

The ThermoWorks Thermapen One closed and not in use on a wooden countertop

(Image credit: TechRadar)


  • Accurate temperature readings in just one second
  • Automatically switches off when not in use
  • Can switch between Farenheit and Celsius

The ThermoWorks Thermapen One is extremely simple to use. Simply unfold the food probe from the side of the thermometer body, insert it into the food item, and the temperature is instantly displayed on the LCD screen in around one second. We found that it was also super-responsive to constantly rising temperatures, such as when heating sugar and egg whites in a bain-marie for swiss meringue buttercream.

We used the Thermapen One for pan-frying steaks, and to check the temperature of reheated lasagne in the microwave. No matter the angle we held the thermometer at when checking the temperature of these foods, the display took less than a second to rotate to the correct orientation for easy reading.

Note that the display orientation can be locked, if you’d prefer, although doing so can be fiddly since it requires the removal of the battery compartment cover and pressing two extremely small buttons several times. These buttons allowed us to customize both the temperature units and the number of decimal places displayed on the thermometer’s screen.  

Meanwhile, the backlight proved to be effective at ensuring we could read the screen in low light, or if the sensor on the main body of the thermostat was covered. 

We were also impressed that, when the thermometer was left unfolded, the display automatically switched off after 30 seconds if the device hadn’t been picked up, in order to conserve battery life. Picking up the Thermapen One immediately reactivated the unit, with the temperature displayed on the screen. The default for this setting is 30 seconds, but this can be customized. 

The ThermoWorks Thermapen One being used to check the temperature of steak

(Image credit: TechRadar)

Battery life

  • Powered by 1 x AAA battery
  • Battery will last up to 2,000 hours before it needs changing
  • Compartment cover is secured with a screw 

The ThermoWorks Thermapen One is powered by a single AAA battery, which the company claims will last for up to 2,000 hours of use before it needs changing – although this figure is for use without the backlight. This is an increase of 500 hours on the 1,500 offered by previous Thermapen models. 

As we’ve already mentioned, the Thermapen One has a new easy-to-access battery compartment that’s secured with just one screw, rather than a cover that could only be removed with the help of a coin.

The back of the ThermoWorks Thermapen One hen it's closed on a wooden countertop

(Image credit: TechRadar)

Should I buy the ThermoWorks Thermapen One?

Buy it if...

You love steak
If you struggle to cook steak to your liking, then the Thermapen One makes it far easier than relying on touch to determine when it’s ready. 

You often cook in low light
Whether you have a particularly dark kitchen, or you often barbecue into the small hours, the backlight on the Thermapen One makes it easy to read the temperature of the food you’re preparing. 

You want a food thermometer for taking out and about
If you often cook on mini-breaks, or you end up playing chef when you’re visiting friends and family, this food thermometer is compact and lightweight, making it ideal to take on your travels. 

Don't buy it if..

You’re on a budget
At $105 / £66, there’s no denying the Thermapen One is an expensive bit of kit. If you’re on a budget then consider more affordable models from Oxo, Salter and in the US only, ThermoWorks. 

You already own the Thermapen Classic
The Thermapen One only offers a handful of upgrades over the Thermapen Classic, so if you own the latter then, in our eyes, the quicker temperature readings and rotating display aren’t worth the cost of upgrading. 

You often customize settings
While the Thermapen One does let you customize settings such as the temperature unit, we found this fiddly to do, so it’s one to avoid if you’re a constant tweaker of settings.  

First reviewed: September 2021

Carrie-Ann Skinner

Carrie-Ann Skinner was formerly Homes Editor at TechRadar, and has more than two decades of experience in both online and print journalism, with 13 years of that spent covering all-things tech. Carrie specializes in smart home devices such as smart plugs and smart lights, as well as large and small appliances including vacuum cleaners, air fryers, stand mixers, and coffee machines. Carrie is now a copy editor at PWC.