The Happy Hacking Keyboard has been around since 1996, and used listings cover most of that history. PFU, the Japanese company that makes it, developed it with the computer scientist Eiiti Wada. The Professional series cuts the usual 104 keys down to 60, which keeps the board small while the keys stay full size. Control sits where Caps Lock usually is, the way it did on early IBM PC keyboards, and a true Delete key sits right above Enter. Every HHKB looks much the same from across the room, so it's easy to buy a different model from the one you meant to. This guide covers how the models differ, how to read the model number, and what to check in the photos.
Where the HHKB came from
The first HHKB used membrane switches and plugged into PS/2, Sun or Apple ADB ports. The Lite models followed in 1999 and 2001, still with membrane switches. The Professional arrived in 2003 and was the first HHKB with Topre electrostatic capacitive switches, which every Professional since has used. It connected with a detachable Mini-USB cable.
The Professional 2 followed in 2006 and added a two-port USB hub on the back. A silenced Professional 2 Type-S came in 2011, in white only. In 2016 the Professional BT brought Bluetooth, running on AA batteries in a bump at the back. Its Micro-USB port only powers the board and doesn't carry data, so it works over Bluetooth alone.
In December 2019 PFU replaced the line with the Classic, the Hybrid and the Hybrid Type-S. All three moved to USB-C, and all three got PBT keycaps on every key, where older models had an ABS space bar. The Studio joined in 2023, and a Classic Type-S followed in October 2025.
The current Professional boards
All four current Professional models use Topre switches at 45g. The differences are the connection and the key structure. Type-S stands for speed and silence in PFU's own description, and the Type-S boards have a 3.8mm keystroke where the standard boards have 4.0mm. Expect a softer, quieter sound from a Type-S.
- The Hybrid Type-S connects by Bluetooth to up to four devices, or by USB-C cable, and runs on two AA batteries. It's PFU's flagship.
- The Hybrid is the same board without the Type-S key structure. It's louder and has the full 4.0mm stroke.
- The Classic is USB-C only, takes no batteries and comes in the English layout only.
- The Classic Type-S is also USB-C only, with silenced keys and legends printed in the center of the keycaps. It's new, so few turn up used yet.
PFU's keymap software works on the Hybrid Type-S, Hybrid and Classic Type-S, and the settings are saved in the keyboard itself. The plain Classic isn't on that list. The Professional boards also have DIP switches on the back for things like swapping Delete for Backspace or changing the Alt and Meta keys.
Reading the model number
The model number is the quickest way to know what's in a listing. Ask for a photo of the box or the label if the seller hasn't shown one. Here's how the codes break down, from the model table on Wikipedia.
- PD-KB800 is the Hybrid in the English layout, and PD-KB820 is the Hybrid in Japanese. A trailing S, as in PD-KB800BS, means Type-S.
- B means the dark charcoal color, W means white and Y means the newer snow color. An N before the S, as in PD-KB800BNS, means blank keycaps with no legends.
- PD-KB401 is the Classic. PD-KB401BSC, WSC and YSC are the Classic Type-S.
- PD-KB400 is the Professional 2, PD-KB420 its Japanese version, and PD-KB600 the Professional BT.
Watch the 820 codes. A PD-KB820BS is a Japanese-layout Hybrid Type-S, with a different set of keys from the English board. If you type in English and want the classic HHKB arrangement, look for 800.
The Studio is a different keyboard
The HHKB Studio keeps the layout and the compact size, and that's where the family resemblance ends. It's the first HHKB with mechanical switches. PFU fits its own silent linear switch at 45g with a 3.6mm stroke, and the switches are hot-swap. PFU says it takes MX-style three-pin and five-pin switches from Cherry, Gateron and Kailh, so you can fit your own. It doesn't use Topre switches of any kind.
It also adds a pointing stick near the center of the board, mouse buttons and touch-sensitive gesture pads for things like switching screens and changing the volume. It runs on four AA batteries or USB power, stores up to four keymap profiles and weighs 840g, against roughly 540g for a Hybrid. Buy one if you want the pointing stick. If you want the Topre feel people mean when they talk about an HHKB, look at the Hybrid or the Classic.
What to check in a used HHKB
- Check the layout in the photos. A Japanese-layout board has extra keys, so make sure it's the one you type on.
- Check whether the keycaps are printed or blank. Blank boards are sold on purpose, so read the model number to see which you're getting.
- Look at the keycaps under good light. HHKB keycaps are PBT with dye-sublimated legends, and dye soaks into the plastic, so the letters shouldn't wear off. A shiny or yellowed space bar on a Professional 2 is the ABS one.
- Ask for a photo inside the battery bump on a Hybrid or BT. Old AA batteries can leak, and the contacts should be clean.
- Ask the seller to type a paragraph on video. Every key should feel and sound the same, with no key sticking or registering twice.
- Ask what the DIP switches are set to. A previous owner may have changed them, and it's easy to set them back.
- On a Studio, ask whether the switches are the stock PFU ones. Hot-swap boards often come with someone else's switches in them.
Which one we'd buy
For most people we'd buy the Hybrid Type-S. It's quiet, it works wired or wireless, and it's the model PFU puts at the top of the line. If you only use one computer, the Classic gives you the same switches and layout with no batteries to think about. A Professional 2 still types like an HHKB and adds the USB hub, as long as you're fine with a Mini-USB cable. Topre is a big part of why people buy these, so read our Topre vs Cherry MX guide if you haven't tried it. You can see every model we cover on the HHKB page or browse what's for sale now.
