Nitecore T4K Feature Image

Review: Nitecore T4K Flashlight

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Compact flashlights are one of those things that you never bother buying, but then really wish you had when trouble strikes. In an emergency or a power outage, or even just when working or walking outside at night, a powerful yet portable flashlight is an essential tool.

And the Nitecore T4K is one of the best of them.

No other flashlight can compare to the power of the T4K, which is able to output 4,000 lumens while easily fitting inside your closed fist. That’s as bright as the high-power headlights on your car.

I got the chance to test out a Nitecore T4K myself and see how it feels to carry, how easy the controls are to navigate, and how versatile this flashlight truly is.

First Impressions

Even though I knew I was reviewing a very small flashlight, I was surprised at just how small it was. The box alone is as big as some flashlights I’ve owned, so when I opened it up and saw the T4K, I was thoroughly impressed at how compact it is.

Nitecore T4K packaging

Inside the box is an instruction booklet, the flashlight itself, a keychain clip, and a charging cord. This is all packed in dense foam to protect the flashlight. The whole presentation is very slick and removing the flashlight almost felt ritualistic, like gently picking up an ancient artifact.

Nitecore T4K - package contents

The flashlight has a nice weight to it—but not enough to weight down your belt when it clips to the keychain. It weighs just less than a pack of playing cards.

One of the obvious features of the T4K is its size and portability. Whether you want a flashlight on-hand for emergencies or if you need it for a midnight stroll, the tiny yet powerful T4K travels and stores easily.

nitecore t4k keychain flashligh 2

As I first experimented with the T4K, the smooth hard-anodized case stood out to me. Having such a clean finish without any bumps or nicks is always a sign of high-quality manufacturing.

When I clicked the flashlight on and began cycling through the five different levels of brightness, I noticed a few things. First, the light is very even. Some flashlights have dark spots within their beam, but the T4K outputs a full-bodied beam of light.

The second thing was just how bright this flashlight can go. I began testing during the evening with just my desk lamp lighting up the room. Even on the flashlight’s middle-of-the-road modes, my visibility skyrocketed. I was able to read the spines of books on a shelf across the room with ease.

When I kicked the T4K into Turbo mode, it blew me away. My initial reaction was that of a deer in headlights: Turbo mode filled the entire room with bright, even light. It was like the sun had risen when I wasn’t looking.

Nitecore T4K from above 2

If you want to see how each brightness mode looks, check out this video.

I found it very easy to navigate between the different modes of the T4K thanks to its OLED display. This provided constant updates on what mode I was in, the lumen output in that mode, the estimated battery life in that mode, and how much battery charge was remaining. The display is bright too, so it is always visible, even when the flashlight is turned off.

The manual seems to include a lot of instructions, but once you start playing with the flashlight it becomes very simple. There are only two buttons after all. Nitecore takes advantage of this and cleverly streamlines the user experience.

Nitecore T4K from front

The top button is the mode select, which toggles between levels of brightness and activates Turbo mode.

The bottom button is on/off, which is also used to activate the lockout modes for safety.

For only two buttons, the range of control you have is remarkable. Between pressing either button individually, pressing both together, and varying the length of the press, you get enough combinations to access every feature all while keeping the flashlight compact and intuitive.


The Nitecore T4K is 3.24 inches long, with a width just under half of that (1.15 inches). It weighs only 2.72 oz.

Nitecore T4K in my hand

When turned to its maximum settings, the flashlight’s beam throw is 209 meters and its luminosity is 4,000 lumens. Four powerful LEDs provide the light, each with its own smooth reflector to maximize beam throw and intensity.

The maximum battery life is 67 hours, or 2.79 days. This is with the flashlight on Ultralow mode, but you can also get a respectable 2.75 hours of runtime on High mode.

For looping the flashlight onto a keychain, it comes with a clip that threads onto a quick-release on the flashlight’s end.

The quick-release detaches with a button press. That way you can keep the clip hooked onto your keychain while being able to detach the flashlight itself, and it snaps back on just as easily. The button takes some real pressure to activate as well, so you won’t accidentally detach the flashlight.

Nitecore T4K - keychain

There is also a large, metal belt clip on the flashlight’s side. There is some serious tension in this thing, which I had to really haul on to be able to slide it onto my belt. This clip is meant to stay put. The clip is extra deep so you can attach it to hat brims or bag straps for hands-free use.

The T4K has a rechargeable 1,000 mAh lithium-ion battery. A USB to USB-C charging cable is included, so you can recharge the flashlight easily from your computer.

Nitecore T4K - charging

Turbo Mode

To access maximum lumen output (4,000 lumens), you switch the flashlight into Turbo mode. This is a limited time mode, because the battery usage starts to heat the flashlight up and it needs a break to cool down. During testing, it never got warmer than a hot cup of coffee—nothing dangerous.

After a short blast of intense luminosity, Turbo mode turns off, but this should never be a problem as turbo mode is truly just for emergencies: high mode is more than enough luminosity for everyday use, and turbo is either for enthusiasts or to scare away something in the dark.

Lockout Mode

The flashlight arrives in lockout mode #2. This means that until a button sequence is pressed, it cannot light up, not even on its lowest settings.

This is meant for more than saving battery during shipping: if you are transporting the flashlight in a backpack or luggage and don’t want it going off, lockout mode prevents it from getting bumped and lighting up. With such a high power flashlight, this is also a good idea for safety, so nobody blinds themselves while playing around with the flashlight.

Lockout mode #1 is also an option, perfect for emergencies. In this mode, the regular flashlight function is still disabled, but Turbo mode is accessible. This way you can still get a quick blast of light at a button-press without any worries about the flashlight accidentally getting turned on while in a bag.

Brightness Modes

The T4K is far more advanced than a simple on/off flashlight. You have five different brightness modes to choose from, each filling a specific need you might want a compact flashlight for.

Ultralow (1 Lumen)

Nitecore T4K - Ultralow 1 lumen - 1

Dim enough you can look into the flashlight without hurting your eyes. Best for navigating your house during power outages or working in small, enclosed spaces where the light doesn’t have room to spread out too much.

Low (15 Lumens)

Nitecore T4K - Low 15 lumens - 2

A good default setting for nighttime-use outdoors, or indoors with some light pollution. Brighter than the flashlight on most smartphones, this mode provides enough light to clearly see the area just in front of you, such as a single sidewalk square.

Mid (65 Lumens)

Nitecore T4K - Mid 65 lumens - 3

Bright enough to have a visible beam sweeping around, and shines even around other light sources such as street lamps. More than enough light to continue simple work in, though you need to start being mindful not to aim it towards other people.

High (200 Lumens)

Nitecore T4K - High 200 lumens - 4

At this point the flashlight is as bright as some light bulbs. It is bright enough to read in without straining your eyes, and shines a strong, bright beam outdoors which gives you good sight lines for anything along a hiking path.

Turbo (4,000 Lumens)

Nitecore T4K - Turbo 4000 lumens - 5

The T4K can only maintain this brightness for a few seconds, so it works best for getting a quick look if something is moving nearby at night or for emergency self-defense. This mode is comparable to turning on floodlights, even outdoors with light pollution. It casts a just visible beam on low-flying clouds.


Whether you are looking for a flashlight to store in an emergency kit, or if you want something to hang on your keychain to use on late-night walks, the T4K is a versatile flashlight for all your needs.


You can purchase the T4K directly from Nitecore or through ordering on Amazon.

Nitecore T4K 4000 Lumen Keychain EDC Flashlight, Super Bright and USB-C Rechargeable with LumenTac...
  • SUPER BRIGHT KEYCHAIN FLASHLIGHT- The Nitecore T4K bursts 10 seconds of 4000 lumen with 228 yards throw on the turbo mode, while maintaining a compact size.
  • ULTIMATE EDC FLASHLIGHT - The keyring has a built-in mechanical quick release design for fast deployment and usage. Additionally, with the included adjustable pocket clip, you have an ideal EDC companion.
  • EASY TO OPERATE - The bright multifunctional OLED display tells you everything you need to know. Use the power switch to turn on/off and the mode switch to cycle through five brightnesses. Hold the mode at any time for instant turbo!