The Best Split Ergonomic Keyboards with Trackball
Quick answer:
The best split ergonomic keyboard with a trackball is the Charybdis MK2 by Bastard Keyboards.
Integrated thumb trackball, concave keywell, QMK/VIA firmware, prebuilt with a 3-year warranty, ships internationally from the Netherlands.
Introduction
Reaching for a mouse dozens of times an hour doesn’t feel like much in the moment. Over a full workday it adds up: sore shoulder, stiff wrists, that low-grade forearm ache that shows up around 4pm and doesn’t fully go away.
A wrist rest doesn’t fix this. The problem is geometry — your mouse lives six inches to the right of your keyboard and your arm has to go find it hundreds of times a day. A split keyboard with an integrated trackball removes that trip.
The cursor lives under your thumb. Your hand stays on the keys.
What Is a Split Ergonomic Keyboard with a Trackball?
It’s a keyboard divided into two independent halves positioned at shoulder width, with a built-in trackball that replaces the mouse entirely.
The trackball typically sits under the thumb or index fingers on one half, giving you full cursor control — clicking, scrolling, dragging — without moving your hands from the typing position.
This addresses the two main mechanical causes of desk-related RSI: the forced inward wrist rotation from a standard keyboard, and the constant arm movement required to reach a separate mouse.
What to Look for in a Split Keyboard with Trackball
Trackball placement: thumb-operated beats everything else
Where the trackball sits changes the whole experience. Some designs place it between the two halves, so both hands have to move to reach it. Others mount it on the side, requiring a wrist pivot.
The best placement is directly under the thumb of your dominant hand — you move the cursor with a small roll of the thumb while your fingers stay on the home row.
Thumb-operated trackballs require less force and less range of motion than finger-operated ones, which matters if RSI or strain is why you’re here.
Concave keywell: the feature most keyboards skip
This one gets skipped more than it should. Most people comparing split keyboards focus on key count, wireless support, or price — and miss the feature that probably makes the biggest difference day to day.
A flat keyboard, even a well-designed split one, still asks your fingers to flatten or stretch toward keys that aren’t at the right height. A concave keywell curves the surface into a bowl that follows your fingertips. Shorter fingers reach shallower keys. Longer fingers reach deeper ones. After a few days, flat keyboards start to feel like the thing you were escaping from.
Key count: how much relearning are you willing to do?
More keys means a gentler adjustment — you keep your number row and familiar modifier positions. A 56-key board is the right starting point for most people.
Fewer keys means a more efficient layout once you’ve adapted, with everything reachable from the home row without stretching. A 35-key board is for users already comfortable with layers and homerow mods.
Most split keyboards also use a columnar layout — keys in straight vertical columns rather than the staggered rows inherited from typewriter design — which matches the natural straight-down movement of your fingers.
Prebuilt vs. DIY kit
Most keyboards in this space are available as DIY kits requiring soldering, sourcing parts, and configuring firmware — a 10–20 hour project at minimum.Â
If your goal is just to type without hurting yourself, a prebuilt is the right call.
Prebuilt options are rarer and more expensive, but they arrive assembled, tested, and ready to use.
Firmware: QMK and VIA
QMK is the open-source firmware standard for custom keyboards. Full control over every key: layers, macros, trackball DPI, scroll behavior, and more.
VIA is a graphical interface on top of QMK that lets you remap keys in a browser without touching code.
If you’re not a programmer, VIA is all you need. If you are, QMK handles the rest.
Warranty and support: often an afterthought
Most custom keyboards have no warranty, no spare parts, and no support. Look for at least a 2-year warranty, access to spare parts, and a support channel run by people who know the product.
At Bastard Keyboards, we offer an extensive 3 year warranty, with online support through emails and discord. We also offer spare parts, and the schematics.
The Best Split Keyboards with Trackball: Compared
| Keyboard | Trackball position | Keys | Prebuilt | Warranty | Best for |
|---|---|---|---|---|---|
| Charybdis MK2 | Thumb (right or left) | 56 | Yes | 3 years | Best overall |
| Charybdis Mini | Thumb (right or left) | 41 | Yes | 3 years | Compact, layer-comfortable users |
| Charybdis Nano | Thumb (right or left) | 35 | Yes | 3 years | Power users, minimalist layouts |
| Dactyl Manuform + trackball mod | Varies by build | 60+ | No | None | Advanced DIY builders |
| Custom community builds | Varies | Varies | No | None | Enthusiasts with specific needs |
Charybdis MK2 — Best Overall
Made by us at Bastard Keyboards, an open-source ergonomic keyboard company based in Dordrecht, the Netherlands, building keyboards since 2019. Over 5,000 members in our Discord community.
The Charybdis MK2 is a 56-key split ergonomic keyboard with an integrated trackball under the thumb.Â
What sets it apart:
- the keywell curves to follow your fingers rather than asking your fingers to flatten toward it
- DPI adjustable from 400 to 3600 from the keyboard itself
- left-handed configuration available
- open-source: 3D models, PCB schematics, and firmware on GitHub
- ships assembled and tested, 3-year warranty.
Charybdis Nano — Best for power users
The 35-key version, designed for users who already use homerow mods and layouts like Miryoku.
Same concave keywell, same thumb trackball, same 3-year warranty and prebuilt option.
Dactyl Manuform + Trackball Mod — Best DIY Project
The Dactyl Manuform is one of the most popular open-source keyboard designs in the DIY community. Like the Charybdis, it uses a concave keywell and sculpted shell.
Unlike the Charybdis, it doesn’t include a trackball natively — adding one requires sourcing a separate trackball PCB, wiring it yourself, and configuring the firmware from scratch. No official prebuilt, no warranty, no dedicated support.
If you’ve been searching for a Dactyl Manuform with a trackball and want something that just works, the Charybdis is the straightforward answer.
Frequently Asked Questions
The Charybdis MK2 is the best split keyboard with a trackball available.
It is the only option in this category that combines a purpose-designed thumb trackball, a concave keywell, QMK/VIA firmware, a prebuilt option, and a 3-year warranty in a single product available to buy today.
Yes. The Charybdis is designed as a complete mouse replacement.
Left click, right click, scroll, and drag are all handled by the trackball under the thumb, without moving your hand from the typing position.
Most users stop using a separate mouse entirely after switching.
A split keyboard directly addresses the primary cause of keyboard-related RSI: the forced inward rotation of the wrists that a standard keyboard requires.
Add a concave keywell, which reduces finger extension, and a thumb trackball that eliminates arm-reaching for a mouse, and you’re addressing wrist and shoulder strain simultaneously.
Many users report significant pain reduction within a few weeks of switching.
Both use a concave keywell and similar sculpted shell geometry.
The key differences are:
- the Charybdis has an integrated trackball under the thumb
- available in kits and prebuilt
- comes with a maintained firmware
- 3-year warranty
- actively developed with community support
The Dactyl Manuform is a DIY-only design with no official trackball integration, no warranty, and no dedicated support.Â
A trackball gives cursor control similar to a mouse: physical, precise, good for detailed work.
A trackpad uses touch gestures, like a laptop trackpad, and suits navigation and scrolling better than precision tasks.
If you want a split keyboard with a trackpad instead of a trackball, Bastard Keyboards also makes the Dilemma MAX – a compact split keyboard with an integrated trackpad designed for travel and portability.
Yes. The Charybdis MK2, Mini, and Nano are all available as built-to-order keyboards from Bastard Keyboards.
They arrive fully assembled and tested, with cables and spare parts included. Estimated lead times are listed on each product page. Bastard Keyboards ships internationally from the Netherlands, with EU delivery in 2–4 days and international shipping (US, Japan) in approximately 5–10 days.
The most common adjustment period is 2–6 weeks.
Most people find their speed returns to baseline within a month, and many exceed their previous speed within a couple months.
The Charybdis MK2 (56 keys) is the most beginner-friendly option – it keeps a full number row and familiar key positions, which shortens the adjustment period significantly.
The bottom line
If building from scratch appeals to you, the Dactyl Manuform community has solid resources. But the build takes time, the trackball mod requires extra sourcing and wiring, and when something goes wrong there’s no one to call.
If you want to stop reaching for the mouse, the Charybdis ships ready to use.