Klarus XT21X Tactical Flashlight Review


Klarus has been really packing in the lumens in compact forms. First they impressed with the XT11GT, a handheld flashlight that delivers 2000 lumens! Then it was the XT11X, another compact flashlight, but it delivers 3200 lumens. They’ve impressed me again with, yet, another tactical flashlight that’s power is out of this world. The Klarus XT21X delivers 4000 lumens and is still a compact handheld flashlight. To say that I was excited to review it is an understatement. I’ve always been a huge fan of Klarus flashlights because they’re insanely powerful, reliable, and packed with a lot of great features. So let’s get started with this review of the Klarus XT21X tactical flashlight.

klarus xt21x flashlight specs

Tactical Flashlight Goodies – What’s in the Box?

First, I want to talk about the flashlight itself as well as the goodies that come with it. So the XT21X is almost an inch longer than the XT11GT and almost half an inch longer than the XT11X. It’s still quite compact, but it’s almost 6.5 inches in length with a head diameter over 1.5 inches. For a flashlight that delivers 4000 lumens, that’s impressive. It’s a good size flashlight to carry in a holster, but you can also clip it onto your pocket as it does have that removable pocket clip.

I really like the look and feel of the flashlight. The design is quite tactical and it’s comfortable in your hand. Klarus has a unique cross-hatching style texture on the body that’s great and prevents the flashlight from slipping.

Klarus does include quite a few things with this tactical flashlight. First, you get a Klarus 21700 battery which we’ll be talking about later on in this review. Along with the removable pocket clip which is already attached to the flashlight, you get a nice nylon holster. It’s a sturdy holster, but it is bulkier than some other holsters I have. While I don’t mind so much, I know other users do prefer lighter holsters. You also get a lanyard, a USB charging cable, and a spare o-ring. There are a good amount of useful accessories which is always a bonus in any flashlight purchase.

accessories xt21x klarus
Multiple Accessories for the Klarus XT21X

Ultra Bright Tactical Flashlight – 4000 lumens!

I think we’re all ready to talk about the power behind this tactical flashlight. 4000 lumens…Whoa. So it has a CREE XHP70.2 P2 LED and features a wide beam. The maximum beam distance is 316 meters. It’s important to know that this flashlight is not a throw light. It does feature a hotspot and has a great spill to it so you can light up the entire area in front of you and see like it’s day time. Seriously, this tactical flashlight is insane.

The XT21X has the same dual tail switch and side switch design that many other Klarus tactical flashlights have. I’ve heard that some users feel like this is a little too much, but I really like it and here’s why. The two tail switches work separately from the side switch so you can use the tail switches or the side switch pretty much interchangeably. I find myself using all of them just depending on the situation. The dual tail switches give you a momentary-on, one touch turbo, and a one touch strobe or a one touch low. With the side switch you get a memory function and a one touch low. There’s a lot to this user interface, but you get the hang of it pretty quickly. I really like that I can operate the XT21X flashlight with the tail switches and with the side switch.

Multiple Outputs and Programmable Settings on Klarus XT21X

Let’s get into the outputs and into the programmable settings. So, the XT21X flashlight features seven outputs giving you a lot to pick from. You’ve got four brightness levels: turbo – 4000 lumens, high – 1200 lumens, medium – 400 lumens, low – 100 lumens, and moonlight – 5 lumens. You also get a strobe and SOS mode. So I want to talk about the brightness levels for a moment. Most high intensity flashlights that Klarus makes has a huge jump in brightness levels. For example, the XT11X goes from high at 400 lumens to turbo at 3200 lumens. It was simply too much of a jump in brightness. I’m stoked to see that the XT21X has a high brightness level of 1200 lumens. I think it was needed and I’m glad Klarus decided to put it in. I’m also glad to see that there’s a moonlight level of 5 lumens. Many tactical flashlights by Klarus feature a low of 10 lumens, but 5 lumens can really help conserve that battery. The maximum runtime on that moonlight mode with a fully charged battery is 200 hours which is phenomenal!

Programmable Tactical Flashlight

Okay, next up is the programmable settings feature. The Klarus XT21X tactical flashlight features two programmable settings that you can switch between at any time. The default is the Tactical Setting where the tail switches give you a one touch strobe. The Outdoor Setting gives you a one touch low with the tail switches. I personally like to keep the flashlight in the Tactical Setting because you have a one touch low with the side switch already. However, it’s great for any outdoor enthusiast or even professional workers who need that one touch low on the tail switches.

It’s fairly easy to switch between the settings, but I recommend keeping your manual. Although Klarus does provide an online manual in case you do lose yours. Unless you’re switching between settings frequently, you may forget how to do it. So make sure to keep that manual handy.

Rechargeable Tactical Flashlight

Rechargeable Tactical Flashlight

As if this flashlight wasn’t cool enough, did I mention that it’s also a rechargeable flashlight? The XT21X features a micro USB port on the side of the flashlight so you can charge it pretty much whenever you need to. No extra batteries. No battery chargers. So long as you have a computer you’re good to go. There’s a charging indicator on the side switch and you can see when the battery is charging (red indicator) and when it’s finished (green indicator).  This also functions as a battery capacity indicator so it’ll glow different colors to let you know what your battery charge is. It’ll glow green when it’s 70 – 100%, yellow or orange when it’s 30 – 70%, red when it’s 10 – 30%, and it’ll flash red when it’s under 10%. This is a pretty great indicator in my opinion. When it comes to rechargeable tactical flashlights, the XT21X is a pretty awesome choice.

Final Thoughts

Pros: There are so many great pros with this flashlight. First, it’s incredibly powerful with its 4000 lumen output. I really like the new body texture on it and it feels great in your hands. I also like the versatility of the three switches, multiple outputs, and programmable settings. Speaking of outputs, I’m over the moon that Klarus added an extra brightness level to go in between the 400 lumens and the 4000 lumens. I also like the moonlight mode of 5 lumens.

Cons: This light is not cheap. If you’re wanting this tactical flashlight, be ready to spend a bit extra on it. It also heats up very quickly. While it has a temperature control system that will drop the output as needed, it still is hot to the touch after having it on turbo for a while.

Conclusion: If you’re looking for a powerful handheld flashlight then you’ve found it. The Klarus XT21X is amazingly bright and is full of awesome features. I haven’t seen a more powerful flashlight that offers everything the XT21X does in such a compact form. Make sure to check out the Klarus XT21X today.