Thermoworks Thermapen ONE Review (Tried and Tested)

The search for the ultimate instant-read meat thermometer can be tough in a world where precision is king. I got my hands on the ThermoWorks Thermapen ONE to test and see if it could live up to its hype of delivering perfect grilled meals every time. 

ThermoWorks Thermapen ONE Review

Having been a loyal user of the ThermoWorks MK4 for what feels like years, I can’t help but rave about everything that makes it what it is: a kitchen superstar. In testing out the ThermoWorks Thermapen ONE, the bar was already set pretty high.

Guess what? The Thermapen ONE comes packed with those awesome features found in the MK4, and is even better. I was blown away by how this gadget surpassed all my expectations: its lightning-fast readings, high accuracy, and reliability was more than impressive. 

Best Instant Read Meat Thermometer
Thermoworks Thermapen ONE

With full readings in ONE second or less, Thermapen ONE approaches the speed of thought - allowing you to focus exclusively on the quality of your work.

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testing the accuracy of the thermoworks thermapen one in a chicken breast that's on a cutting board outside in my outdoor kitchen.

My Experience With the Thermapen

The Thermapen ONE thermometer is very simple and ready to go, right out of the box – I love when brands make it easy to use their products immediately.  

The first thing you’ll notice after taking the Thermapen ONE out of the box is how close it is in size to the Thermapen MK4. 

At only 6.1 inches tall, 1.7 inches wide, and 0.74 inches thick, the Thermapen ONE feels better in your hand and gives you a sense of higher-quality craftsmanship. 

The attention to detail in its construction gives a sense of durability and reliability, making it feel anything but cheap.

I appreciate the micro-thermocouple at the probe’s tip, giving you precise temperature measurements. It’s impressive how a mere 1/8″ insertion depth is enough to get accurate readings!

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Testing the Thermoworks Thermapen

Features and Benefits

In the culinary world, the Thermoworks Thermapen ONE is hard to beat when measuring temperatures accurately. But, beyond that, this innovative tool offers many cutting-edge features that can transform the way you cook. 

Solid Construction

Top-notch thermometer brands prioritize creating a tool that users actually enjoy holding. This design is high quality, and it feels great in my hand. I can tell they designed this thermometer with ergonomics in mind.

One thing I really appreciate about the design is the sizable rotating LCD screen which allows me to take accurate readings quickly regardless of how I insert it into the meat. Plus, I don’t have to crane my head to read the numbers.

This thermometer is IP67 waterproof and designed for outdoor use. As someone who grills a lot, this is a must for me. I’ve also tested its waterproof capabilities when I (accidentally) dropped it into a simmering stew pot. Even after being submerged in the stew, the thermometer still works great.

And don’t get me started on the number of times my father-in-law has dropped it over at my house. It’s resilient, to say the least. 

Motion Activated Display

ThermoWorks has also ingeniously tackled the battery life hurdle by integrating motion-sensing sleep and wake functionality. When you have been inactive for a defined time (which can be adjusted in the “Settings” mode), the Thermapen ONE automatically turns off and turns back on when you pick it up again. 

Precise Temperature Readings

There’s one golden rule regarding instant-read thermometers: be as precise and accurate as possible. The Thermapen ONE offers precise temperature readings with decimal-based temperatures, which gives you even more accuracy with your cook. This means, rather than the temperature only reading 130°, it will show 130.4°. 

I found the ability to read decimal temperatures significantly improved in this newer Thermapen model compared to older versions, such as the Thermapen Classic.

That said, I have an older Thermapen that can only display whole numbers (like 78 degrees) instead of decimal temperatures (like 78.2 degrees). This was a knock for many, and now they’ve solved that.

In terms of its accuracy, the Thermapen ONE is accurate with both low and high temperature ranges, which can’t be said for many other thermometers I tested. In my testing of other thermometers, most break down as temperatures exceed 130°-140°. Not the Thermapen.

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testing the screen brightness and rotation of the thermoworks thermapen one

Thermapen Update

ThermoWorks has truly outdone itself with the Thermapen ONE. They took their already highly acclaimed MK4 thermometer and made some great enhancements. The result is a thermometer that provides quicker read times, heightened accuracy, and improved construction.

Improved Display and Warranty

The backlight in this was brighter and more responsive than I expected – I’m confident I could use it to signal passing planes based on how bright it gets. The transition from the orange background in the MK4 has improved readability, especially in low-light conditions. 

I was also pleased by the improved full five-year warranty of the new Thermapen ONE, compared to the two-year warranty that came with the previous model.

Improved Read Time and Accuracy

With the older MK4, it took about two or three seconds to get a reading after placing it in an ice bath. With the Thermapen ONE, you get that same reading within one second. 

In the new model, you’ll enjoy an enhanced accuracy to within 0.5 degrees Fahrenheit, which is an improvement from 0.7 degrees Fahrenheit in the MK4 model.

Now, with cooking meat, we’re most concerned with accuracy at ranges from 120° on the low end, all the way up to 170 ° on the high end. Take a look at my images, using a sous vide for water temperature accuracy. The Thermapen is very accurate.

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Benefits and Drawbacks

It is difficult to find something wrong to say about the Thermapen ONE. Here’s what I love:

  • The ability to read decimal temperatures is really helpful in allowing you to control the temperature precisely to see if it reaches the FDA-recommended minimum safe temperature  
  • The LED light is very bright, especially in low-light conditions
  • The waterproof capability is undoubtedly a valuable enhancement, boasting an impressive IP67 rating
  • The one-second read time capability is highly convenient, especially when you measure meat over the grill flames and don’t want to burn your hands
  • Impressive build quality and ergonomic design make this thermometer nice to hold

Here’s a downside to the tool: 

  • While the Thermapen’s performance is top-notch, I can’t ignore the elephant in the room  – the higher price tag. For those of us watching our wallets, it might give us a little sticker shock.
comparing the thermapen to other instant read thermometers

Comparing the Thermapen One to Competitors

When comparing the Thermapen ONE to similar products, its speed and precision outperform any other instant-read thermometer. 

It delivers internal temperature readings with a superb accuracy of 0.5 degrees Fahrenheit in just one second. No competing product can compare to its exceptional performance.

Thermapen ONE vs. ThermoPop 2

If you want something a bit more affordable that’s not quite as precise or fast, ThermoWorks offers the ThermoPop 2. While it includes some of the features found in the Thermapen, it takes 2-3 times as long to display temperature readings. 

I also find the ThermoPop 2 slightly less comfortable to hold than the Thermapen, and it’s not as accurate in my testing (especially at high temperatures). But it’s still very good for the price.

If you value an extended warranty for that extra peace of mind, the Thermapen ONE is worth considering as it gives you even more reassurance in your investment.

Read our full ThermoPop 2 Review.

Thermapen ONE vs Weber Instant Read

The Weber Instant Read is less accurate than the Thermapen ONE, and sometimes to a wide degree (especially at high temperatures). 

Ergonomically, the Weber just can’t compete with Thermapen’s impressive design. However, with its smaller size, it can easily stick up in meat without falling over, unlike the Thermapen ONE. 

Read our full Weber Instant Read Meat Thermometer Review.

Thermapen ONE vs ThermoPro TP19H

I found the ThermoPro to be a reliable performer, coming in a close second to the Thermapen ONE in terms of accuracy at a fraction of the price.

Although it did decently at higher temperatures, I have to admit that its ergonomic design left something to be desired, as it doesn’t flip horizontally or vertically. 

I had to awkwardly crane my neck to read the temperature, which was quite bothersome. I don’t have that issue with the Thermapen.

Check out our full ThermoPro TP19H review.

If you’re still not sure, check out another option in our review of the ChefsTemp Finaltouch X10.

a look at the size of the thermapen one

Who Should Get a Thermapen?

If you’re looking to upgrade from a cheaper thermometer you have or want something that will last for years, the Thermapen ONE stands out as the best instant-read thermometer you can invest in. 

I’d also recommend the Thermapen to those who take grilling, baking, or sous vide cooking seriously, where precision and consistency are essential for consistent, high-quality food.

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Shawn Hill

Hey, I'm Shawn and I love this site. With a wife and 7 kids, I get most of my grilling practice from feeding my own family. I'm here to help you learn more about grilling, smoking, and backyard BBQ! With almost a decade of manning the grill and helping over 25,000 aspiring grill masters, you're in great hands! I've tried just about every type of grill, accessory, and gadget you can imagine. Because of that, I am here to help guide you to the best of the best and help you save time and money by avoiding the junk.

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