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ThermoWorks Thermapen ONE Digital Meat Thermometer Review - The Grilling Life

In this ThermoWorks Thermapen ONE digital meat thermometer review, I will be giving you the Pros, the Cons, and the Facts about the New ThermoWorks Instant Read Meat Thermometer.

Did the best instant read digital meat thermometer money can buy just get replaced by something better?

In this article, I aim to find out!

It’s no secret that the ThermoWorks MK4 instant read digital meat thermometer is considered by most in the BBQ and cooking industry to be the gold standard for testing food temperature doneness.

With the release of the all-new ThermoWorks Thermapen ONE, it looks like the MK4 has a real challenger.

In fact, ThermoWorks is so confident that the Thermapen ONE will outperform the MK4 in every way, that they are discontinuing the MK4 as soon as supplies run out.

So, if you’re thinking about purchasing a new instant read meat thermometer, there is a new top-of-the-line option from which to select! The Thermapen ONE has joined the ranks.

In this ThermoWorks Thermapen ONE review, I will cover its description and features so that you’re armed with the right information when you decide to take it to the next level.

Next up, I’ll cover my personal experience testing the Thermapen ONE and verify whether it is as fast and accurate as it claims to be.

And of course, I’ll also share two vital details to consider when making any significant investment when adding to your grilling our cooking tool kit: the manufacturer’s warranty and the customer service the manufacturer provides its customers.

Finally, I will include some of my personally curated pros and cons, so you’ll have the most complete and comprehensive overview.

Let’s get to it, shall we!

If you are interested in checking out the MK4 before they are gone, check out my complete ThermoWorks MK4 Review including links to purchase one at a discounted rate while supplies last.

*Disclaimer: “ThermoWorks provided me with their Thermapen® ONE for testing at no charge in return for my honest review and feedback.  All thoughts and opinions expressed herein are my own and are not influenced by the developing company and/or its affiliates in any way.”

Thermapen ONE Quick Facts

Product Name: ThermoWorks Thermapen ONE Digital Meat Thermometer

Made By: ThermoWorks®

Top 4 Features:

  • ONE second or less read time
  • Improved accuracy spec of ± 0.5°F (± 0.3°C)
  • Brighter Backlight
  • A newly designed battery compartment with easier access to setting controls

ThermoWorks Deals

ThermoWorks Thermapen ONE Digital Meat Thermometer Review And Rating - The Grilling Life

What’s New with the Thermapen ONE

Before we begin, there are several improvements and design changes to point out. I’ll give you a quick rundown of what’s changed below. Then I’ll cover these changes in depth, so you’ll have a good understanding of possible benefits the new Thermapen One.

Read Time:

  • MK4 – Full readings in just 2-3 seconds, which is second only to the Thermapen ONE in speed.
  • Thermapen ONE – One second read times.


  • MK4 – Accuracy to ±0.7°F (±0.4°C)
  • Thermapen ONE – Improved accuracy spec of ± 0.5°F (± 0.3°C)

Automatic Backlight:

  • MK4 – Display automatically illuminates in low light conditions.
  • Thermapen ONE – Display also automatically illuminates in low light conditions but is brighter and the light sensor is more sensitive to changes in ambient lighting settings.

Battery Compartment:

  • MK4 – Small removable compartment that makes it harder to access settings.
  • Thermapen ONE – newly designed battery compartment for easier access to the user settings.


  • MK4 – Has a manufacturer’s warranty of 2 years.
  • Thermapen ONE – The newly designed and extra rugged, waterproof case features a 5-year warranty against defects.

The Thermapen® ONE Meat Thermometer Description & Features

The super-fast Thermapen® ONE adds on to the classic and MK4 Thermapens with some much-requested upgrades while keeping the same aspects that make the Thermapen brand one of the most trusted in the industry.

The Thermapen ONE at a Glance

  • ONE. Second. Readings.
  • Industry-leading accuracy to half a degree: ± 0.5°F (±0.3°C)
  • Brighter, ultra-responsive automatic backlight
  • -58.0 to 572.0°F (-49.9 to 299.9°C) temperature range
  • 4.3 L inches, High-Performance Type K Thermocouple Probe
  • 10 to 180 seconds, user-selectable sleep mode
  • Shockproof, dustproof, and waterproof with an IP67 rating
  • 2,000-hour battery life (when not using the backlight)
  • Motion-Sensing Sleep and Wake Mode
  • Patented 360° auto-rotating display
  • Foldaway design protects probe when not in use
  • Display temperatures in °F or °C, 1° or 0.1° resolution
  • Includes NIST-traceable calibration certificate
  • 5-Year Warranty

Read Time

If you haven’t guessed it by now, the Thermapen ONE is named for its one-second read times.

So why do the extra 2 seconds read time matter from the old MK4? Well for the average backyard warrior, it may not.

But for anyone that has tried grilling or cooking multiple dishes at the same time, or if you are in a barbecue competition or work in the restaurant industry, 2 seconds can make a difference between perfection or disaster.

Reading temperatures at one second or less makes the super-fast Thermapen ONE about as close to instant as you can get with an instant read thermometer.

Highly Accurate

The accuracy of the Thermapen ONE is fantastic and as good as it gets.  It comes within ±0.5°F of the exact temperature of what you are checking.

That is hands down as accurate as I have seen in a publicly available food thermometer product.

Intelligent Backlight Technology

An intelligent backlight means you don’t have to squint or use a flashlight to read the thermometer at night (or in a dark oven).

After using many thermometers without backlight technology over the years, I can say from personal experience, a backlight display is worth a few extra bucks alone.

And now it is brighter than ever.

If you’ve ever found yourself standing beside your grill at night with tongs in one hand, thermometer in the other while trying to hold a flashlight between your lips, you know exactly what I mean.

And here is the intelligent part.

The ONE is designed to sense when it is dark outside and will light up the display automagically making it easy to read at dusk or in total darkness.

180° Rotating Probe & 360° Auto Rotating Display

The far rotating probe makes it super simple to get at any strange angle you need.  Checking the temperature of a turkey or a crowded grill full of chicken wings has never been simpler.

The foldaway probe design protects it from accidental damage when you are done using it.

The auto-rotating display makes that even easier.  When you turn the thermometer to any of the four directions, the display appears upright for you making it super easy to read.

In other words, no matter which direction you hold or turn the thermometer, the display will always be right-side up.

Motion Sensing Auto Power Sleep & Wake Mode

Another awesome feature of the Thermapen ONE thermometer is its automatic power.  When you open the probe, the thermometer turns on, fold the probe back to closed and it turns off.

But it goes beyond that.

If you set the thermometer down for a short period of time (even while folded open) it will automatically turn off to save battery power.  A motion sensor turns the thermometer back on when you pick it up, so there is no hassle in turning it on and off constantly between temperature checks. 

You can even configure the auto-sleep mode to activate between 10 seconds to 3 minutes depending on your preference.  All pretty high-tech and intuitive stuff if you ask me.

Waterproof To IP67

ThermoWorks had improved on their splash resistant original Thermapen by increasing the water resistance on the MK4 making it shockproof, dustproof, and waterproof.

This hasn’t changed on the Thermapen ONE as you still get all the benefits of IP67 protection.

Does this mean you can wash it?  Yes, that is exactly what this means. It is still not dishwater safe, but it is rated for safe immersion in water up to 39” depth for up to 30 minutes. You can hand wash your Thermapen ONE after every use.

If you are like me and tend to leave the cleanup of the grill and equipment until after you eat and occasionally forget and leave things outside overnight, this is a great new upgrade.

New & Improved Battery Compartment

Why am I wasting your time talking about a battery compartment? Because in my opinion, the new design is a big improvement.

The controls for adjusting the settings are much bigger, clearly labeled, and simpler to manipulate compared to the older version. The battery compartment opening is much larger overall, making it easier for bigger fingers to maneuver around. Changing the battery is just a lot easier.

In the big picture, this is not a huge deal, but it is another example of ThermoWorks paying attention to customer feedback and their desire to create the best products available.

ThermoWorks Thermapen ONE Updated Battery Compartment

10 Colors to Choose From

ThermoWorks always offers an assortment of colors, which is a nice little way to personalize your thermometer.  This way, you can get the color that exactly matches your cooking equipment.

My Personal Experience Testing the Thermapen ONE

I’m always excited to test out new BBQ equipment but a new ThermoWorks product is always fun. My expectations are extremely high when it comes to ThermoWorks products and they have not failed me yet.

So, I jumped right in to see what the ONE instant read thermometer could do. I put it through the wringer many times.

Here are a few of my favorite highlights.

Speed Test

I’m used to fast temperature read times after using various MK4’s over the years so I wasn’t expecting much of a difference. I was shocked that I actually noticed a big difference in the speed.

After testing them both side by side many times, the ONE was hands down the winner. It was fast. This is the biggest improvement over the MK4, in my opinion, hands down.

Intelligent Backlight

The Intelligent Backlight worked the same, but the big difference is the brighter display. It is much easier to read even in the daytime with the glare from the sun.

The old display had a yellowing backlight and was not that bright. The new display has a clear and brighter display that is a big improvement.

Improved Battery Compartment

With easier access to the controls and the single AAA 1.5v battery, ThermoWorks made a big improvement.

The controls let you customize the sleep and wake settings, adjust the display resolution, change the temperature readings from °C to °F, etc. The new larger settings panel makes it much easier for making changes even if you have larger fingers.

NIST-Traceable Calibration Certificate

Before ThermoWorks ships any of their Thermapen ONE thermometers, it is thoroughly tested. Once approved, it will ship with a NIST-Traceable calibration certificate guaranteeing accurate temperature readings.

ThermoWorks Thermapen ONE NIST-Traceable Calibration Certificate

Thermapen ONE Pros & Cons

The biggest con in buying the Thermopen ONE is its cost. It is one of the most expensive thermometers around for its general ability. It is understandably priced as high as it is, because of the overall build, features, and accuracy. But the price can certainly turn some people away.

The pros for the Thermapen ONE instant read meat thermometer go on and on.

The accuracy and read time make it the best thermometers around, so it is hard to argue with it based on that alone. Its automatic rotating display and far reaching probe make it a very convenient product to use.

The auto lighting display also helps with nighttime convenience. The auto power feature is also awesome, and hard to beat.


Improved, industry leading read time of 1 second

Incredible Accuracy to ±0.5°F

Intelligent backlight technology with bright display

180° rotating probe & auto-rotating display

Auto Power And Sleep Mode

Waterproof, dustproof, shockproof

Color personalization options


Costs more than the average instant-read thermometer

You cannot leave it in the grill or oven while cooking

Thermapen ONE Warranty & Customer Service

As stated before, the Thermapen ONE comes with a full five-year warranty against defects in either components or workmanship.

Compared to most other competitors on the market offering only a standard 12-month warranty, this is huge.

ThermoWorks also offers world-class customer service with multiple ways to contact them. On their website, you can even connect instantly through a live chat feature. Their chat agents are super helpful and friendly.

The included instruction manual that comes with every purchase offers contact info as well by listing an email address, physical address, telephone number, and website URL.

Final Thoughts on Our ThermoWorks Thermapen ONE Digital Meat Thermometer Review

The Thermapen® ONE digital meat thermometer is one of the best instant read thermometers around.  In fact, I will go so far as to say that Thermoworks makes the best cooking thermometers in the world.  They do a lot of things right but they do one thing really, really well and that one thing is, read accurate temperatures!

Oh, and faster than anyone else too. Wait, is that two things? Ok, they do two things really, really well!

Thermoworks always puts out a great product, but the new Thermapen ONE is above and beyond the competition.  If it is within your price range, it is definitely worth checking out.

It’s get’s a five out of five stars from The Grilling Life!

Now It’s Your Turn

I want to hear from you:

Which instant read thermometer have you used before?

Do you have any thermometer tips to share?

What features do you typically like to see in an instant read thermometer?

Are you going to be purchasing a smoker in the future?  Or do you plan on looking at a pellet grill, built-in gas grill or standalone gas grill, or charcoal grill?

Let me know by leaving a quick comment below.

If you still have questions, please feel free to send me a message.




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Patrick Ginise

Grillmaster/Web Owner

Patrick Ginise

A backyard warrior, certified carnivore, lover of good whiskey, grill master and I’m Living The Grilling Life!

I have a passion for cooking with live fire and smoke, no matter the weather. I’m a real person just like you, who loves outdoor cooking and BBQ. Food, fun, and time spent with family and friends are what it’s all about! It is my mission to take my passion and knowledge for outdoor cooking and all things BBQ and share this expertise in techniques and grilling equipment with you. In other words, Living The Grilling Life!

I have personally tested over 150+ Grills and Smokers and hundreds of grilling thermometers, temperature controllers, grill brushes, grilling tools, fire starters, and other BBQ products.