Feker JJK21 vs Leobog K21DIY Kit vs Pre-Built Numpad Choice
Choose the Feker JJK21 for a premium, customizable typing project, or the Leobog K21 for a lighter, ready-to-use accessory.
Which one should you get?
Get the
Feker JJK21
DIY Kit
- Gasket mount design with a PC plate for a softer, bouncier typing feel.
- Sold as a complete DIY kit including case, PCB, foam, stabilizers, plate, and battery.
- Includes a programmable knob for media control or custom functions.
- Requires assembly, as it is a DIY kit, not a pre-built product.
- Heavier at 300g, which may reduce portability.
- Some user reviews note an automatic sleep mode in wireless modes that can cause a missed first keystroke.
Get the
Leobog K21
Pre-Built Numpad Choice
- Pre-built and ready to use out of the box.
- Lighter weight of 200g for easier portability.
- Includes PBT and ABS keycaps and comes with pre-lubed Leobog Crystal switches.
- Smaller 600mAh battery capacity.
- Uses a standard plate mount instead of a gasket mount.
- Lacks a knob for additional control or programmability.
Select the Feker JJK21 if you enjoy building keyboards and want a premium gasket-mount typing feel with a programmable knob for macros or media. Opt for the Leobog K21 if you prefer a lighter, pre-built numpad that works immediately and has explicit cross-platform support. Both are capable wireless peripherals, but they cater to different user engagement levels.
The differences that matter
Skip the 40-row spec sheet. These are the specs that change how each board feels, sounds, and fits your desk.
Feker JJK21
Leobog K21
Battery
1,500 mAh
600 mAh
Mount style
Gasket Mount
Plate Mount
Knob
Yes
No
Weight
300 g
200 g
Plate material
Plastic
Polycarbonate
- Feker JJK21
- Leobog K21
- Performance
- 7774
- Build quality
- 7561
- Productivity
- 7480
- Customizability
- 8071
- Portability
- 8689
- Layout size: Numpad
- Connection: Bluetooth, 2.4 GHz, Wired
- Hot-swappable
- Case material: Plastic
- Sound dampening
What will you mostly use it for?
The Leobog K21 wins for office use and travel due to its pre-built nature and lighter weight. The Feker JJK21 is the clear choice for modding, programming, and content creation, thanks to its DIY kit format, programmable knob, and macro software. For gaming, both are equally capable on paper. The choice largely depends on whether you value a project (Feker) or a plug-and-play accessory (Leobog).
It's a tie
- Both offer N-key rollover for simultaneous key presses.
- Both support low-latency 2.4GHz wireless and wired modes.
- Neither has a stated advantage in polling rate or gaming-specific features.
What owners say
Ratings and quotes collected from verified store reviews, including the critical ones.
Feker JJK21
10 owner reviews
“This numpad has been one of my favorite recent purchases. The wireless is very snappy and painless to pair. I use it to pull out when I need to enter a lot of numbers for work but then put it away for playing games. Its a great little addition and it even has…”
“キーを打つ度にドンドンと机を叩くような低い音が響くので、柔らかいリストレストの上に置いて使っています。 ライティングの設定は、しばらく続けるとなぜか変更を受け付けなくなるので、その度にリセット(多分Fn+Esc長押し)を押しています。 Windowsを起動した直後にpinを入れるためにキーを押しても反応が鈍く、入力をやり直す機会が増えたことも不満です。 追記 接続は、PC側もUSB-Cで繋ぐと安定しました。 ライティングを点滅させるとNumランプも一緒に点滅するので視認性が悪いです。…”
Leobog K21
No owner reviews collected yet.
Feker JJK21 vs Leobog K21 specs
Every tracked spec, side by side. Rows marked with a dot differ between the boards.
6 of 20 specs differ
Feker JJK21
Leobog K21
Hot-swappable
Mount style
Sound dampening
Layout size
Layout standard
Ergonomics
Knob
Display
Connection
Battery
USB-C
Case material
Plate material
Keycaps
Weight
Dimensions
Backlight
N-key rollover
Mac & Windows
Released
Compare prices
Live prices from the stores we track, cheapest in-stock offer first.
Lowest price across stores, Amazon excluded.
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Feker JJK21 vs Leobog K21: your questions
The core difference is that the Feker JJK21 is a DIY kit featuring a gasket mount and includes a knob, while the Leobog K21 is a pre-built numpad with a plate mount and is ready to use immediately. This makes the Feker a project for enthusiasts and the Leobog a straightforward accessory.
The Feker JJK21 has a 1500mAh battery, which is larger than the Leobog K21's 600mAh battery. Based on capacity alone, the Feker should offer longer usage between charges, though actual battery life depends on usage patterns and RGB settings.
Yes, both the Feker JJK21 and Leobog K21 feature hot-swappable PCBs that support 3-pin and 5-pin mechanical switches. This allows you to easily swap switches without soldering on either device.
Yes, according to its vendor description, the Leobog K21 is a pre-built unit. It includes keycaps made of PBT and ABS and comes with pre-lubed Leobog Crystal switches installed.
The Feker JJK21 kit includes the case, PCB, EVA foam, stabilizers, positioning plate, and a 1500mAh battery. You need to provide your own switches and keycaps to complete the build, as it is sold as a barebones kit.
The Feker JJK21 is noted for its programmable software. User reviews mention successfully setting macros, and its included knob can also be programmed for custom functions, giving it an edge for macro programming over the Leobog K21.
The Leobog K21 explicitly lists Mac support in its features. The Feker JJK21's vendor description only mentions Windows XP/7/8/10 for its software, though the hardware may still function on a Mac for basic input.
The Feker JJK21 uses a gasket mount system with a polycarbonate (PC) plate, which typically offers a softer, more cushioned typing feel. The Leobog K21 uses a standard plate mount system.
A user review for the Feker JJK21 notes an automatic sleep mode in its Bluetooth and 2.4GHz wireless modes that can cause the first keystroke after inactivity to not register. This issue is not mentioned for the Leobog K21 in the provided information.
The Leobog K21 is more portable due to its lower weight of 200g compared to the Feker JJK21's 300g. Both have similar compact, 21-key layouts and support wireless connectivity for cable-free use.
Yes, both numpads feature RGB backlighting. The Feker JJK21 listing mentions several RGB effects and colors, while the Leobog K21 listing also confirms RGB and white backlighting.
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