The Best Foam for Keyboards (Ultimate Guide)

Let’s be real, most keyboards sound… kinda sad out of the box.

Hollow. Pingy. Like you’re typing on a plastic lunch tray in a middle school cafeteria.

But don’t worry! There’s an easy fix that doesn’t involve soldering, switch lubing, or wading though the r/MechanicalKeyboards chaos.

That fix is: keyboard foam mods.

If you’ve never heard of it before, no worries.

By the time you finish this article, we’re gonna make sure know everything from the best foam for keyboards to where to put them.

So, let’s not waste anymore time and get into this guide!



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What Does Keyboard Foam Actually Do?

Keyboard Case Foam
Keyboard Case Foam

You know that hollow, plasticky echo your board makes? Foam fixes that.

Here’s what keyboard dampening foam brings to the table:

  • Deepens your keyboard’s sound, especially with linear switches
  • Reduces pinging and metallic reverb from your case or plate
  • Tightens up the feel of each keystroke
  • Improves the overall quality of your typing or gaming sessions

And honestly, it’s one of the cheapest, easiest mods out there.

If your keyboard sounds like a cheap toy or vibrates like a tuning fork, foam can be a game-changer.

But it’s not just about silencing things. Really, it’s about customizing your sound signature.

Want that deep, buttery “thock” that sounds like popcorn popping? Foam helps get you there.

Prefer a softer, more muted tone for those quiet office environments or late-night game grinds? Foam’s got your back.

Plus, the right foam in the right place can also make your keyboard feel more stable and less rattly, especially on boards with a lot of empty space inside.

So yeah, it’s not just a sound mod, it’s an entire experience upgrade.

Be sure to pair it the right switches. We’ll teach you all about switches here.



Where Foam Goes Inside Your Keyboard

Drop CSTM80 Keyboard
Drop CSTM80

You don’t need to fill your board with foam like it’s a Build-A-Bear.

Instead, you place it strategically in one (or more) of these common spots:

Case Foam (Bottom Layer)

Foam placed in the bottom of your case helps eliminate hollowness and vibrations.

This is where Poron, EVA, Sorbothane, or even polyfill work well.

This is best for a big, instant improvement in sound.

You’ll need to avoid going too thick as it can make the case hard to close.

Learn more about keyboard cases here.

Plate Foam (Between Plate and PCB)

This goes between your plate and your PCB.

It helps absorb the impact of each keystroke and smooths out harsh clacks.

It’s best for creating a softer, cleaner sound.

Be sure to watch the amount because it’ll make your switches feel mushy if it’s too thick.

Learn more about keyboard plates here.

PE Foam (On Top of PCB)

This is the “PE mod” everyone talks about.

A thin foam layer between your PCB and switches gives you that poppy, marbly “thock” sound.

It’s best for getting that satisfying deep tone.

Keep in mind that it might not work well with all switch types.



The Best Types of Foam for Modding Keyboards

Now that you know where they’re supposed to go, let’s get into the best types of foam for keyboards.

We’ll cover everything from budget options to audiophile level and pre-cut kits to DIY sheets you can slice up with scissors.

Poron Foam

Poron Foam
Poron Foam

Best for: Case foam, plate foam

Sound: Deep, muted, luxurious

Feel: Soft, squishy, flexible

Why we love it: It absorbs sound beautifully without making your board feel mushy

Buy pre-cut: Poron Foam Kit – Plug and Play

DIY sheets: Poron Foam Sheets – Easy to Cut

EVA Foam (Ethylene-Vinyl Acetate)

EVA Foam
EVA Foam

Best for: Case or plate foam

Sound: Subdued, firmer than Poron

Feel: Slightly stiffer, still absorbent

Why we love it: Cheap, easy to work with, and better than leaving your case empty

Buy pre-cut: EVA Kit – Good Value Pick

DIY sheets: EVA Foam Sheets – Trim to Fit

PE Foam (Polyethylene)

PE (Polyethylene) Foam
PE Foam

Best for: PCB layer (PE mod)

Sound: Crisp, poppy, marbly

Feel: Doesn’t affect feel, just changes sound

Why we love it: Great for gaming boards that need punchy feedback

Buy pre-cut: PE Mod Kit – Ready for Thock

DIY sheets: PE Foam Sheets – Get That Pop

Neoprene

Neoprene Foam
Neoprene Foam

Best for: Case foam

Sound: Subtle, clean, and tight

Feel: Very firm, dense

Why we’re cautious: It’s harder to work with, and results vary

DIY sheets: Neoprene Sheets – Thick and Dense

We don’t recommend neoprene for first-time modders. It’s tough to cut, unforgiving if you mess up, and doesn’t always improve the sound as much as you’d hope.

Sorbothane

Sorbothane Foam
Sorbothane Foam

Best for: Case foam only

Sound: Extremely dampened, vibration-killing

Feel: Super soft, heavy, sticky

Why it’s interesting: It’s what scientists use to isolate vibrations, seriously

Watch out: It’s pricey, messy to handle, and a little overkill for beginners

DIY sheets: Sorbothane Sheets – Extreme Dampening

Great for sound-obsessed builders, but it’s like putting racing tires on your first car. Maybe save it for round two.

Polyfill

Polyfill
Polyfill

Best for: Case foam

Sound: Soft, pillowy, surprisingly decent

Feel: Light and airy

Why it’s fun: Dirt cheap and found in old pillows or at craft stores

Caution: Can compress over time and shift around

Buy a bag: Polyfill Stuffing – Budget Hero

If you’re on a budget or just want to experiment without breaking the bank, this is a fun one to try. Just don’t overstuff it.



Foam Comparison Chart


Foam TypeUse LocationSound StyleFeelBeginner Friendly
PoronCase, PlateDeep, cleanSoft⭐⭐⭐⭐⭐
EVACase, PlateMuted, firmMedium⭐⭐⭐⭐
PEPCB (PE mod)Crisp, marbly, thockyNo change⭐⭐⭐⭐
NeopreneCase onlyTight, subtleVery firm⭐⭐
SorbothaneCase onlyExtremely dampenedUltra soft⭐⭐
PolyfillCase onlySoft, airyLight and fluffy⭐⭐⭐⭐


So… What Foam Should You Use?

KBD8X MKIII Foam Kit
KBD8X MKIII Foam Kit

We’ll make it easy for you with some suggested guidelines:

Just want a better-sounding board fast? Go with Poron case foam. Drop it in, close it up, and enjoy the thock. It’s flexible, forgiving, and instantly takes that cheap, hollow tone down a few notches.

On a budget? Try EVA foam or even polyfill (way better than leaving your case empty). EVA is cheap and easy to find, while polyfill is basically free if you’ve got an old pillow lying around. Either one can take your board from clacky chaos to pleasantly muted in minutes.

Craving that TikTok-level thocky pop? Add PE foam under your switches and let your keyboard sing. It’s the go-to for that soft, marbly sound that mechanical keyboard YouTube and Instagram reels love to flex. Bonus: it doesn’t change how your board feels, just how it sounds.

Tinkerer or audiophile? Give Sorbothane a shot. It’s messy but magical (just don’t say we didn’t warn you). It’s dense, sticky, and incredibly effective at stopping vibration dead in its tracks. If you’re chasing a truly dampened, low-pitched typing experience, it might be your new favorite thing.

Avoid neoprene for now. It’s a little advanced, and there are easier wins out there for first-timers. It’s stiff, it’s tricky to cut, and it might not make a dramatic difference unless you already know what sound you’re going for.

Remember, you don’t need to fill every possible spot with foam right away.

START WITH ONE LAYER, test it out, and build from there.

Modding is half science, half art.

The more you tweak and experiment, the more you’ll learn what sound and feel you actually like.



Foam Your Way to a Better Keyboard

Let’s be real, you don’t need to build a $400 custom keyboard to get that premium typing sound.

A couple layers of well-placed foam can totally transform how your board sounds and feels.

Just a few sheets of the right foam can kill annoying case echo and deepen your typing sound.

Whether you’re laying down ranked matches, hammering out reports, or just chilling in Discord, keyboard foam mods can turn a mediocre keyboard into something you actually enjoy using.

So, what are you waiting for? Grab some foam and start modding!



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