Electrostatic Capacitive Keyboard HHKB HYBRID Type-S Review

Preface

As a Vim user (VS Code paired with the Vim extension), my perspective when writing this article may carry some natural bias. Everyone’s keyboard preferences differ, so please take this as personal reference.

Back in February of this year, I spent an entire day typing and writing code. At the time, I was using a mechanical keyboard (FILCO Majestouch MINILA Air with Cherry MX Brown switches) and noticed my fingers becoming quite fatigued, leaving me with a sense of weakness whenever I typed.

So, I took this opportunity to try out what many consider the pinnacle of the keyboard world—and a dream keyboard for countless software engineers—the HHKB. Having used it thoroughly since purchasing, I’m extremely satisfied and wanted to share my experience. Beyond my hands-on impressions of the HHKB, this article also explains the mechanics behind electrostatic capacitive keyboards.

Keyboard Categories

First, a brief overview of the main types of keyboards:

Membrane Keyboards

The kind of keyboard you can pick up at an electronics store for a few dollars; it’s the cheapest keyboard design available. When a key is pressed, conductive rubber makes contact with the circuit board to close the circuit, allowing the keyboard’s microcontroller to detect the change. While convenient, the membrane loses elasticity over extended use, and multi-key rollover is prone to inaccuracies, making it not necessarily the best choice for people who use keyboards for long hours.

Mechanical Keyboards

Mechanical keyboards operate on a principle similar to membrane keyboards: pressing a key closes a circuit, allowing the microcontroller to detect the keystroke. However, mechanical keyboards achieve this through springs, metal contact leaves, and switch stems. When a key is pressed, two metal leaves make contact, completing the circuit. Depending on the stem design, these switches are categorized into Blue, Red, Brown, Black, and more, each offering a distinct typing feel. The presence of a spring also provides strong tactile feedback.

Electrostatic Capacitive Keyboards

Now to the star of the show: electrostatic capacitive keyboards.

Electrostatic capacitive keyboards detect keystrokes through changes in capacitance. By placing two parallel electrode plates near each other, the space between them gains the ability to store an electrical charge. Applying an appropriate voltage across the two plates charges this capacitor. Capacitance is inversely proportional to distance: the closer the plates, the higher the capacitance; the higher the capacitance, the greater the voltage across the capacitor.

The microcontroller uses an ADC (Analog to Digital Converter) to monitor changes in voltage. When the voltage exceeds a certain threshold, it registers as a keypress. It’s worth emphasizing that the microcontroller does not directly monitor capacitance changes, but rather voltage changes.

The biggest difference between electrostatic capacitive keyboards and others is that they have no physical contact points—the circuit remains continuously connected. Because there are no contact points, there is no component wear-and-tear, typing noise is significantly reduced, the lifespan is longer, and there is no mechanical click/bump.

It is also worth emphasizing that the electrical conduction principle itself doesn’t determine typing feel. What dictates feel is the design of the conical springs and rubber domes. Therefore, even among electrostatic capacitive keyboards, manufacturers can craft vastly different typing feels depending on their design choices.

Why Are Electrostatic Capacitive Keyboards So Expensive?

Next, let’s explore why electrostatic capacitive keyboards carry such a high price tag. In my view, there are two primary reasons: “fundamental differences in detection method” and “manufacturing process.”

Fundamental Differences in Detection Method

As mentioned above, standard keyboards only need to detect whether an electrical circuit is closed or open. In contrast, capacitive keyboards must monitor continuous analog voltage changes to determine if a key is pressed, making both circuit design and firmware substantially more complex.

Furthermore, the capacitance of the electrode plates in these keyboards is typically on the order of a few picofarads ($10^{-12}\text{ F}$). Such minuscule capacitance is highly susceptible to electrical noise, so eliminating noise interference to prevent false keystrokes requires significant engineering effort.

Manufacturing Process

Manufacturing electrostatic capacitive keyboards is far more intricate than producing mechanical or membrane keyboards. Makers must ensure the capacitance values across every single key position are nearly identical, and considerably more effort must be poured into PCB design. You can check out the video below at 3:42 to see the internal structure of an HHKB:

(As a side note, the typing feel comes entirely from the internal springs and rubber domes.)

For these reasons, very few companies manufacture electrostatic capacitive keyboards, and their pricing tends to be high, which naturally limits the target audience.

Taking HHKB as an example, the top-tier model—the HHKB Professional HYBRID Type-S—costs around ¥35,200 (2021 data, roughly 9,000 NTD). A great keyboard lasts for years; some of my colleagues have used theirs for decades, to the point where the plastic has yellowed. From a long-term perspective, this price isn’t really expensive—it’s an investment!

Currently, the most prominent brands in this space are Realforce and HHKB. Recently, the Chinese brand NiZ has also gained considerable popularity, offering a much more accessible price point.

Although the HHKB market in Taiwan is relatively niche, its brand awareness in Japan is massive. In my current company alone, over 100 people use an HHKB daily, not to mention those who own two.

HHKB (Happy Hacking Keyboard)

HHKB stands for Happy Hacking Keyboard. Originally co-designed by Eiiti Wada, Professor Emeritus at the University of Tokyo, and PFU Laboratories, its first version debuted in 1996, marking its 25th anniversary in 2021.

Regarding HHKB, the most famous quote comes from HHKB’s creator, Dr. Wada:

アメリカ西部のカウボーイたちは、馬が死ぬと馬はそこに残していくが、どんなに砂漠を歩こうとも、鞍は自分で担いで往く。馬は消耗品であり、鞍は自分の体に馴染んだインタフェースだからだ。 いまやパソコンは消耗品であり、キーボードは大切な、生涯使えるインタフェースであることを忘れてはいけない。

When cowboys in the American West had their horses die on them, they would leave the horse behind, but no matter how far they had to walk across the desert, they always carried their saddle. The horse was a consumable, but the saddle was an interface tailored to their own body. Never forget that today, PCs are consumables, but the keyboard is an essential interface you can use for a lifetime.

PFU’s website also features an invited paper titled Please Pay Your Attention to the Keyboard Layout, which explains why HHKB’s layout diverges from conventional keyboards. I highly recommend reading it!

HHKB’s Keyboard Layout

HHKB was originally designed for programmers, so many key placements are tailored to optimize coding efficiency. However, even if you aren’t a developer, once you get used to the layout, you should be able to master it easily—developers will just appreciate the benefits even more directly.

The HHKB layout embraces pure minimalism, stripping away all non-essential keys to arrive at just 59 keys. The image above clearly highlights the differences between HHKB and standard keyboard layouts:

① Tab and Caps Lock Share the Same Position

Caps Lock isn’t used frequently in general programming (most people just hold Shift for capitals), yet on standard keyboards it occupies prime real estate. Therefore, in the HHKB layout, a dedicated Caps Lock key is omitted; pressing Fn + Tab acts as Caps Lock instead.

This might be slightly inconvenient for Mac users, as many use Caps Lock to toggle input methods, unless your daily workflow only ever requires Chinese input.

① The Position of Ctrl

The Ctrl key sits right where Caps Lock normally is, to the left of A. It takes some getting used to, but once you adapt, you’ll realize this design is brilliant: your pinky finger no longer needs to stretch awkwardly. In Vim, navigating with Ctrl+F, Ctrl+B, and Ctrl+W becomes effortless, and hitting Ctrl+C in the terminal to terminate processes is just as smooth.

② No Arrow Keys

HHKB has no dedicated arrow keys! If you want to move up, down, left, or right, you must press Fn + [ / ; ' simultaneously, or remap them via software. If you play games requiring arrow keys, you’ll need to reconfigure your setup. I rest my pinky on the Fn key and steer with my other fingers, which also took some time to get used to.

If your coding style relies heavily on arrow keys for cursor navigation, this may feel cumbersome, as anchoring your pinky on Fn can cause fatigue. This was actually my catalyst for adopting Vim; now I navigate almost exclusively with hjkl.

② DELETE Sits Directly Above Enter

In standard layouts, the key directly above Enter is backslash (\). On the HHKB, this spot is replaced by DELETE (functioning as Backspace). The most immediate benefit is a noticeably shorter reach for your finger when hitting Backspace.

③ Placement of \ and `

On the HHKB, both \ and ` are moved to the row above DELETE. It felt a bit odd at first, but over time it wasn’t an issue since neither key is used with extremely high frequency anyway.

Once you master the HHKB layout, the single biggest benefit is that your hands barely have to stretch. For anyone who spends long hours typing, true efficiency comes from moving swiftly across the keys while minimizing physical movement—leading to drastically reduced fatigue over extended sessions.

Typing Feel

For those accustomed to mechanical switches, the typing feel of an electrostatic capacitive keyboard may initially seem strange, or even off-putting. Due to the contactless design, capacitive keyboards lack a sharp tactile click or the acoustic clatter of switch latches, making the sensation distinctly different from mechanical keyboards. I strongly recommend borrowing one from a friend or trying it out in person before buying, as typing feel is ultimately personal.

Pros

Ideal for Long Typing Sessions

Electrostatic capacitive keyboards generally require lighter actuation force, making them well-suited for marathon typing and coding sessions. I made the switch to HHKB precisely because my fingers felt exhausted after spending full days typing on a mechanical board.

Strictly in terms of raw tactile punch, I think mechanical keyboards still have a slight edge. However, HHKB’s feel has a unique charm of its own—simply sitting on the desk, it has a magnetic pull that invites you to type.

Highly Portable

The model I currently use weighs just 540g and measures roughly 30cm × 10cm, making it an excellent companion to pack alongside a tablet or laptop.

Unique Layout

Although it demands an initial adjustment period, once you become fluent with the HHKB layout, programming feels significantly more fluid. Furthermore, the push to avoid arrow keys nudged me into mastering Vim, which turned out to be a great bonus.

Cons

Proprietary Keycaps

Most mechanical keyboards use Cherry MX-compatible stems, but HHKB keycaps are manufactured by Topre, meaning the two ecosystems are incompatible.

If you want to swap out keycaps for custom sets, finding vendors takes real effort, and the selection is far more limited. If you have a 3D printer at home, you could try printing your own, but the quality won’t match factory standards.

Expensive

A keyboard at this price point is definitely a major commitment. Not only is the board itself pricey, but the accessories are equally steep. When my keyboard arrived, I realized it didn’t come with a dust cover—I had to shell out ¥4,400 for the official lid. The matching wooden palm rest, while replaceable by cheaper third-party options on Amazon, runs another ¥4,400 if you want the official PFU version. Buying the board along with all official accessories will put a serious dent in your wallet.

Battery Replacements

I tend to leave the keyboard powered on all the time, which likely contributes to faster battery drain. Using it roughly 8 to 10 hours a day, I find myself swapping batteries roughly once a month.

Layout Adjustment Friction

Once you get muscle memory locked into HHKB’s layout, jumping onto someone else’s standard keyboard feels remarkably jarring and requires conscious readjustment. Additionally, the lack of dedicated F1–F12 keys means relying on Fn combos, which could be a significant pain point for anyone whose workflow hinges on function keys. Personally, I prefer compact boards, so it hasn’t been a big issue for me.

Hard to Buy in Taiwan

There are virtually no physical retail channels to purchase an HHKB directly in Taiwan. You typically have to rely on proxy buying services or forwarders via Amazon JP (there were rumors they stopped shipping directly to Taiwan?), which keeps HHKB discussions somewhat niche locally. Currently, the easiest and most economical route is picking one up while traveling in Japan. However, standard retail electronics chains rarely stock HHKB keyboards; if you want to try one out in person, check the HHKB Official Showroom Guide, which lists demo spots across Tokyo, Osaka, and Nagoya.

HHKB Model Overview

The current HHKB lineup consists of three primary models: HHKB Professional HYBRID Type-S, HHKB Professional HYBRID, and HHKB Professional Classic. Each model is available in Charcoal (Black) and White, with both printed and blank (unprinted) keycap variants. Here is a brief breakdown:

Classic

The wired-only version of the HHKB, and the most affordable entry point in the lineup.

HYBRID

HYBRID denotes that the keyboard offers both Bluetooth and wired connectivity.

The HHKB Professional HYBRID Type-S I currently use lets you switch seamlessly between wireless and wired modes. It can pair with up to four Bluetooth devices—perfect for multi-device workflows. For instance, you can connect to your office PC, pair with your laptop on the go, and switch to your home rig with a simple Fn + Ctrl + [1-4] key combination.

However, the keyboard runs on two AA batteries rather than having an internal rechargeable pack. While you can use rechargeable AA batteries (like Eneloops), it remains a slight inconvenience, and battery consumption feels fairly swift—requiring fresh batteries roughly once a month. My laziness in never turning off the power switch probably plays a role here.

HYBRID Type-S

Type-S represents the silent version. In addition to the dual Bluetooth and wired connectivity of the HYBRID, the key switches are engineered to be quieter than the standard HYBRID—though not completely silent. You can hear the sound comparison in this YouTube video (starting at 10:12):

If you purchase directly from PFU, make sure to choose the English (ANSI) layout instead of the Japanese (JIS) layout! The two layouts are completely different.

Conclusion

To wrap things up, typing feel is fundamentally subjective. While I personally love the HHKB experience, there will certainly be people who cannot get used to it. Particularly for those coming from mechanical keyboards, the absence of sharp tactility creates a bigger difference in sensation than you might expect, so trying one out beforehand is highly recommended. With the Japanese Yen at historic lows, now might just be the best time to pick one up.

May everyone find their endgame keyboard in the chaotic world of key switches.

Additional References

• [Twitter Share] The HHKB so cool it appeared in a Japanese drama; Japanese ATM keyboards are capacitive too?! This article notes that the keyboard used in the Japanese drama I Will Not Work Overtime, Period is an HHKB. Japanese 7-Eleven ATM keypads also use electrostatic capacitive switches.
• HHKB Pro2 Keyboard Review One of the few detailed Chinese reviews of HHKB, covering an earlier model generation.

Further discussions in Chinese can be found on PTT’s Key_Mou_Pad board.

Japanese resources are far more abundant:

• HHKB Official Stories & Interviews HHKB regularly interviews prominent users and publishes feature stories on their site.
• The Origin Story of HHKB
• Sanzai TV - HHKB HYBRID Type-S Review
• Tobalog - HHKB HYBRID Type-S Comparison with Previous Models

Additionally, PFU does an outstanding job managing their Twitter account, actively interacting with HHKB community members almost daily, fostering strong brand loyalty, and adeptly tying current trends back to HHKB.