Mini-ITX and small form factor (SFF) PCs are all the rage these days, and we wouldn’t blame you for wanting to get in on the hype. But building a compact rig comes with its own challenges, like finding the best low-profile CPU cooler to fit in such tiny cases.

Most mainstream Mini-ITX and SFF cases limit you to between one and a half to three inches of CPU cooler clearance. So we’ve opted to limit ourselves to low-profile CPU coolers shorter than three inches, focusing on the ultra-compatible sub-two-inch coolers. But we’ve also included a taller option for those with extra room to spare. Let’s get started.

Our Favorite Low-Profile CPU Coolers

Before we start, we should remind you that these low-profile CPU coolers generally work best with lower-TDP CPUs and those running at stock clocks. Many reviewers test these coolers with high-end or overclocked CPUs running synthetic benchmarks, resulting in seemingly excessive CPU temperatures.

While some numbers you’ll see later might seem alarming, don’t worry! Gaming workloads don’t stress CPUs as much as AIDA64 or Intel Burn Test, so you’ll see lower temps across the board in general. Pairing your low-profile CPU cooler with a suitable processor will also help keep temperatures down. We discuss CPU and cooler pairings later in our buying guide, but feel free to skip ahead if you want.

1. Noctua NH-L9 Series (LGA115x, LGA1700, AM4)

* Noctua’s NSPR is an in-house rating that indicates cooling performance in relation to other Noctua products. Higher numbers are better.

Noctua’s NH-L9 family of low-profile CPU coolers offer great cooling (for their size) and an excellent affordable price, making them an easy choice for anyone needing a bonafide small form factor CPU cooler.

Coming in at 1.45 inches tall, the NH-L9 CPU coolers will fit almost anywhere, even in some of the smallest Mini-ITX cases available. This effortless compatibility makes them an easy default choice for the majority of SFF builders. Of course, the great performance for the size helps too.

APH Networks tested the (all-black, but otherwise identical) L9a-AM4 chromax.black version with a Ryzen 7 3700X at stock clocks, putting it up against some larger Noctua coolers. The tiny L9a acquitted itself well, keeping the CPU at 83 degrees Celsius even under a heavy Prime95 load.

That might not seem impressive, but remember that the L9a-AM4 is less than 1.5 inches tall and has a single 92 mm fan to move air through the heatsink. In that context, the L9a-AM4 did exceedingly well. You’ll likely see lower temperatures in daily use, especially when gaming. Prime95 is notoriously heavy on the CPU, so the temperatures here are an extreme example and arguably not reflective of regular use.

Solid cooling aside, you also get a predictably premium package if you opt for any of the NH-L9 coolers. You get a low-noise adapter, a tube of Noctua’s highly-regarded NT-H1 thermal compound, and a class-leading six-year warranty. The AM4 versions also come with a backplate, which you’ll need to install to your motherboard.

Overall, Noctua’s NH-L9 coolers are an excellent and ultra-compatible choice for any SFF build, no matter which CPU or socket you’re building with. The only issue, perhaps, is the lack of cross-socket compatibility, meaning you need different versions depending on your CPU socket (or buy an adapter kit). But that’s a small price to pay for this level of compact cooling.

Need a bit more cooling? If you have a compatible case, you can boost the L9 coolers’ performance by using Noctua’s NA-FD1 duct kit. It creates a tunnel between the fan and your case’s perforated side panel, improving airflow and reducing temperatures.

If you’re not keen on the traditional brown-and-browner Noctua look, the NH-L9i and NH-L9i-17xx are also available in all-black versions.

2. Alpenföhn Black Ridge

If you need more cooling performance than Noctua’s NH-L9 coolers, Alpenföhn’s Black Ridge is the low-profile CPU cooler you want. Its design means you’ll have to make some sacrifices you won’t have to make with other low-profile coolers, but the performance might be worth it for you.

The main issue with the Black Ridge is its dimensions; while the 1.85-inch height isn’t too bad, the heatsink takes up more horizontal room than most others. For one, it overhangs the RAM slots slightly, so you’ll need to use low-profile RAM shorter than 1.29 inches.

In addition, the heatsink may also interfere with your motherboard’s top PCIe slot, depending on the layout. Alpenföhn recommends using a PCIe riser cable for your GPU if you want maximum compatibility, making the Black Ridge one of the more inconvenient CPU coolers to use.

On the positive side, however, the Black Ridge’s performance more than makes up for any convenience issues. It’s an excellent performer for its size.

Tech-Legend tested the Black Ridge on an Intel i9-9900K at stock and 5.0 GHz overclocks and found that it traded blows with Noctua’s significantly taller NH-L12S. The Black Ridge was only slightly worse when overclocked (90 degrees vs. the NH-L12S’s 89 degrees Celsius) and outperformed the Noctua at stock (79 vs. 85 degrees) clocks.

The Black Ridge couldn’t stop the overclocked i9-9900K from thermal throttling with a full-scale AIDA64 load, but that’s not really much of a surprise. Alpenföhn only advertises 95-watt TDP compatibility for the Black Ridge, and a 9900K running at 5.0 GHz is way past that.

Unfortunately, one area where the Black Ridge stumbles is in its noise output. While it handily outperforms the Noctua NH-L9i in Tech-Legend’s testing, it does so at the cost of significantly more fan noise. Tech-Legend measured 34 dBA from the L9i at around a foot away; in contrast, the Black Ridge hit 43 dBA measured from the same distance.

So no, the Alpenföhn Black Ridge isn’t a perfect cooler that’ll work for everyone. Its higher noise output and compatibility issues make it an option you’ll have to build around to get the best out of it. But these likely won’t be deal-breaking issues for those who demand the best possible cooling performance from a low-profile CPU cooler under two inches.

Want to use the Black Ridge with an Intel Alder Lake CPU? Fill in this form and Alpenföhn will send you the LGA 1700 upgrade kit for free.

3. Cryorig C7 RGB

Cryorig’s C7 RGB is one of the few compelling aftermarket low-profile CPU coolers with RGB, so it’s worth a look if you want some visual flair for your small form factor PC. But it’s more than just style over substance, as the C7 RGB is also an adequate performer adequate for most low-powered builds.

The C7 RGB performs roughly on par with AMD’s low-profile Wraith Stealth stock cooler, which comes as stock with most of the company’s Ryzen 5 and Ryzen 3 CPUs. Basic Tutorials put the C7 RGB up against the Wraith Stealth and got identical results with an AMD Ryzen 5 2400G.

Both coolers hit 79 degrees Celsius after 15-minute runs of Prime95, the only difference being a minute single-degree difference once they introduced an 80 mm case fan. In that setup, the Wraith Stealth dropped to 77 degrees, while the C7 RGB ended at 78 degrees.

If you consider that the Wraith Stealth also has RGB and comes free with an AMD CPU, the C7 RGB might seem like a bad deal. But there are two situations where we think the C7 RGB makes sense.

Firstly, the C7 RGB has better cooling performance than the stock cooler on most Intel CPUs, especially those that shipped with LGA 1200 and 115X CPUs (like the Intel Core i5-11400F). So the C7 RGB will have a clearer advantage if you’re running one of those. Secondly, the C7 RGB is also noticeably shorter than the Wraith Stealth, at 1.85 inches vs. the AMD cooler’s 2.12 inches.

While that won’t be an issue for most builds, the C7 RGB is perfect for compact small form factor cases with less than two inches of CPU cooler clearance. If you’re building in one of those, the Wraith Stealth’s 2.12-inch height puts it out of contention; that’s where the C7 RGB comes in.

The Cryorig C7 RGB won’t be for everyone or every build. But if you need its combination of sub-two-inch height and RGB fan, it’ll likely be the best low-profile cooler option for you.

4. ID-Cooling IS-40X

ID-Cooling’s IS-40X is one of the most affordable low-profile coolers on the market, but that doesn’t mean it’s not a capable option. It’s a solid performer and a safe choice provided you pair it with a suitable CPU.

SFF.Network tested the IS40v3, a differently-colored predecessor to the IS-40X that is otherwise identical, with an Intel Pentium G3258 at various clock speeds. They ran the G3258 at a number of different clock speeds, from a sedate 3.0 GHz up to a hefty 4.5 GHz overclock, to really put the ID-Cooling through its paces.

The ID-Cooling unit offered decent cooling performance here, managing a respectable 37.0 degree Celsius overclock at 4.0 GHz. The 4.5 GHz numbers weren’t as impressive, with the temperature nearly doubling to 60 degrees Celsius over ambient. The huge gap isn’t surprising considering the extreme voltage requirements to hit 4.5 GHz. The G3258 needed 1.373 volts to hit 4.5 GHz, compared to the 1.17 volts for 4.0 GHz.

However, it’s important to note that these numbers were with the fan running at its maximum 2500 RPM and putting out a lot of fan noise. Lowering fan speeds via the motherboard BIOS’ “silent” setting reduced fan speeds to a much more acceptable 1483 RPM at the cost of reduced cooling performance. For example, the 4.0 GHz delta increased from 37 degrees to 42 degrees; still OK, but not quite as impressive.

It’s not an ideal trade-off, but we consider it acceptable considering the budget and low-TDP focus of coolers like these. Overall, ID-Cooling’s IS-40X is a solid budget offering that’ll do a decent job with low- or mid-power CPUs. It won’t win any awards for performance or size, but it’s hard to be too critical of it considering the price.

5. Noctua NH-L12S

* Noctua’s NSPR is an in-house rating that indicates cooling performance in relation to other Noctua products. Higher numbers are better.

Not everyone building a small form factor PC has to deal with a two-inch limitation on their CPU cooler. If you have a bit more room and want improved cooling (or the ability to run slightly hotter CPUs), the Noctua NH-L12S is one of your strongest options.

The NH-L12S takes the general design of low-profile CPU coolers like the NH-L9 but adds some much-needed room between the heatsink fans and the cold plate. This provides more room for airflow and helps bring temperatures down. It still can’t compete with a proper tower cooler, but the performance is noticeably better than sub-two-inch coolers.

Tech-Legend tested the Noctua with an Intel i9-9900K at stock clocks and with a 5.0 GHz overclock, the latter of which is arguably beyond the “low overclocking headroom” Noctua claims with this combination. Even then, however, it acquitted itself reasonably well, hitting 85 and 89 degrees Celsius stock and overclocked, respectively.

The NH-L12S failed to stop the overclocked 9900K from thermal throttling in AIDA64’s much more brutal testing, but that’s hardly a surprise. The Noctua wasn’t designed to handle that much heat, especially not in a punishing synthetic test like AIDA64. Stick to stock clocks and non-synthetic workloads, and you should be fine even with a CPU of this caliber.

Fan noise levels are good, too, with Tech-Legend measuring a decent 31 dBA at around a foot away. So you won’t have any serious noise issues here, provided you’re not overloading the cooler.

Note that you can install the NH-L12S’ fan above (push) or below (pull) the heatsink. The former setup increases RAM clearance to 1.77 inches, while the latter minimizes the cooler height for tighter installations. It’s a nice touch that makes it a more flexible cooler than its competitors.

Overall, the Noctua NH-L12S is arguably the default choice for anyone seeking a slightly larger low-profile cooler. It won’t fit into the tiniest of cases, so you’ll have to be a bit more aware of clearances. If you have room for it, though, it definitely won’t disappoint. The low price is just icing on the cake.

Before You Buy

Do You Need a Low-Profile Cooler?

If you’re building in a Micro-ATX case or larger, the answer is “no.” You can use one, sure, but there’s no real reason. You’ll have enough room for a mid-sized tower cooler that will perform much better.

How much better, you ask? Let’s revisit Tech-Legend’s Noctua NH-L12 review, paying attention to the NH-L12’s temperature results compared to a decent CPU tower cooler.

The Scythe Ninja 5 dominates the NH-L12S here, with roughly 30-degree Celsius deltas between it and the NH-L12S at both stock (53 vs. 85 degrees) and overclocked (63 vs. 89 degrees) settings. Yes, the Ninja 5’s dual towers take up a lot of space, but it’s still only 6.1 inches tall. That’s short enough to fit in a Micro-ATX case without issue.

However, let’s say you’re building in a case like the Lian Li Q58 (one of our favorite Mini-ITX cases). The Q58 only has enough room for a 2.6-inch tall CPU cooler, which isn’t enough for a tower cooler. In this situation, you’ll want either a low-profile cooler or an AIO to keep your CPU cool. This, conveniently, brings us to our next topic.

Low-Profile Coolers vs. AIOs

If you’re in the market for a low-profile CPU cooler, you’ll likely have to choose between one of the CPU coolers on our list or an AIO, most probably a 120 mm AIO. Each has pros and cons, so let’s quickly run through some reasons why you may or may not want to pick one over the other.

As is traditional in the air vs. liquid cooling debate, air coolers will have the advantage in pricing and reliability. There’s precious little that can go wrong with air coolers, and the only part that might fail—the fan—is easily replaced. So a low-profile CPU cooler will be an affordable, zero-maintenance part that you can easily carry over to new builds, socket compatibility permitting.

An AIO, on the other hand, has more potential failure points. The pump can go bad, your tubes can leak, and there’s always the issue of coolant drying out through permeation. Most AIOs also tend to have a five-to-six-year life, so you’ll be replacing them more regularly than air coolers.

AIOs also cost more, with a decent 120 mm AIO like the Arctic Liquid Freezer II 120 costing almost double that of our top Noctua pick. However, the extra cost might be worth it, as a decent 120 mm AIO will generally outperform a low-profile air cooler.

Note how the 120 mm Corsair Hydro H60 (on the far right) beats even the Noctua NH-L12S in The Tech Buyer’s Guru testing. This isn’t with some ultra-high-power CPU, either: they ran the tests with an AMD Ryzen 5 3600 at stock clocks. So you can benefit from an AIO even with a mid-range CPU.

The downside, of course, is fan noise: Corsair’s H60 hit 52 dBA, whereas most low-profile air coolers tended to stay around or below 40 dBA. So that’s a compromise you’ll have to make if you want the better temperatures an AIO can provide.

Whether the lower temps are worth it (or necessary) depends entirely on how you feel about AIOs. Are you OK with the combination of decreased longevity, extra cost, and higher noise? In that case, then an AIO is likely the better choice. But if you want a simpler and quieter rig and don’t mind a few extra degrees on the CPU, stick with a cheaper low-profile air cooler.

Choosing the Right CPU

The most crucial part of building an SFF rig is selecting a suitable CPU. In a bigger case, you’d just get a CPU with enough grunt for the tasks you need, but that changes when putting together a compact rig that you’ll have to cool with a low-profile cooler (or small AIO).

In that situation, you’ll want to find a balance between your CPU and cooling solution to keep temperatures under control. The standard (if flawed) way to evaluate whether your CPU and cooler combination works is TDP (thermal design power). All CPUs will have a claimed TDP number that indicates how much heat they produce, while coolers will have a TDP that they’re supposed to be able to cool.

If your cooler’s rated TDP is higher than your CPU’s TDP, the combination should work on paper. However, this is problematic because most (if not all) CPUs run hotter and use more power than their TDPs might suggest. So a “95-watt” TDP CPU might actually put out 150 watts or more at full load.

Thankfully, things have changed slightly with Intel’s latest CPUs. The company now lists “Processor Base Power” and “Maximum Turbo Power” ratings for their CPUs instead of a single TDP figure. Their Core i5-12400, for example, has a rated base power of 65 watts and uses around 75 watts in the real world. So it’s not a one-to-one match, but it’s more accurate than the old TDP numbers.

Want to play it safe? Get a Noctua cooler. The company has excellent CPU compatibility lists for all of its coolers. These lists grade CPU compatibility from “incompatible” to “best overclocking/headroom.” We highly recommend checking the list before you buy a CPU or a Noctua cooler to see whether your chosen combination will work.

While we’re here, it’s worth reminding you to consider CPU socket compatibility before buying a low-profile CPU cooler. Due to their compact nature, some manufacturers opt to release separate versions of a low-profile air cooler for different sockets.

Noctua’s NH-L9x coolers are a great example. There are three versions: one for 11th-Gen and older Intel CPUs (NH-L9i), one for 12th- and 13th-Gen Intel CPUs (L9i-17xx), and one for modern AMD CPUs (L9a-AM4). They’re not interchangeable and, by default, will only work with the specific sockets Noctua designed them for.

However, Noctua sells mounting kits that will allow you to install these coolers on different sockets. For example, the NM-AM5-L9aL9i mounting kit lets you use the NH-L9i and L9a-AM4 (but not the L9i-17xx) on AM5 (AMD Zen 4) CPUs. There’s also the NM-AM4-L9aL9i mounting kit, which converts the L9i (and old, non-AM4 L9a) to work with the AM4 (AMD Zen 1 to Zen 3) socket.

It’s confusing for sure, so double-check before buying to ensure that you’re getting the right Noctua cooler. It’s not as big an issue with most other manufacturers, as they stick to one product for both AMD and Intel sockets. But you should still check before buying to avoid disappointment.

Closing Thoughts

The best low-profile CPU coolers are must-haves for anyone building a compact SFF or HTPC rig. They’re not the most capable coolers in terms of raw performance, but their small size and relatively low noise output make them perfect for the low- and mid-range CPUs common in smaller builds.

If you need an ultra-compact, low-profile CPU cooler that’ll fit almost anywhere, one of the Noctua NH-L9 products should be perfect for you. The NH-L9i-17xx paired with a modern 12th-Gen Core i3 should make for a brilliant small gaming rig, for example. If you’re on a tighter budget, the ID-Cooling IS-40X offers solid cooling for roughly $30.

All the best!