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Niuniu KB40 - 40% Custom Keyboard Kit

Niuniu KB40 Mechanical Keyboard

The NIUNIU KB40 Electrocapacitive is a 40% mechanical keyboard kit designed for hobbyists and enthusiasts who want a compact layout with electrocapacitive switch compatibility. It suits users who value a small footprint and the option to customize with both MX-style and electrocapacitive switches. The kit format requires assembly and some familiarity with keyboard building.</p... Read more
Compare prices from $170.00 to $200
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Niuniu KB40 - 40% Custom Keyboard Kit

MonacoKeys
MonacoKeys
No shipping to US
$170

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Compare Niuniu KB40 vs KBDFans Agar Mini vs Keychron Q4 Pro Specification

Compare similar keyboards side by side, or use the comparison table to compare all keyboards!
Niuniu KB40KBDFans Agar MiniKeychron Q4 Pro
70
Niuniu KB40 - 40% Custom Keyboard Kit
94
Ready to use Agar mini Dual-mode version with keycaps
90
Keychron Q4 Pro QMK/VIA Wireless Custom Mechanical Keyboard
0.0 (0)
4.5 (4)
5.0 (2)
  • Released in 2026
  • Offers Ortholinear ergonomics
  • Supports Bluetooth, 2.4 GHz, Wired, Wireless connectivity
  • Released in 2025
  • Supports VIAL configuration
  • Supports Bluetooth, Wireless, Wired connectivity
  • Equipped with a 1000 mAh battery
  • Weighs about 700 g
  • Sized at 40 x 250 x 120 mm
  • Made with a Polycarbonate, Brass, Aluminum case
  • Released in 2023
  • Has Linear, Tactile, Clicky switch options
  • Available in a 60% layout
  • Built with the ANSI, ISO layout standard
  • Supports Bluetooth, Wired, Wireless connectivity
  • Equipped with a 4000 mAh battery
  • Weighs about 1351 g
  • Sized at 21 x 121 x 303 mm
  • Features PBT keycaps
  • Offers Yes, Rgb, South-face, Rgb South-face RGB lighting
Scores
  • Performance: 45
  • Build Quality: 72.5
  • Productivity: 76.7
  • Customizability: 62.4
  • Portability: 87.7
Scores
  • Performance: 63.1
  • Build Quality: 94.2
  • Productivity: 94
  • Customizability: 95
  • Portability: 86.9
Scores
  • Performance: 75.2
  • Build Quality: 87.3
  • Productivity: 91.1
  • Customizability: 95.3
  • Portability: 89.5
Name
Niuniu KB40
Name
KBDFans Agar Mini
Name
Keychron Q4 Pro
Release year
2026
Release year
2025
Release year
2023
Switch Options
-
Switch Options
-
Switch Options
Linear, Tactile, Clicky
Profile
Normal Profile
Profile
Normal Profile
Profile
Normal Profile
Hot Swappable
 
Hot Swappable
 
Hot Swappable
 
Layout Size
40%
Layout Size
40%
Layout Size
60%
Layout Standard
ANSI
Layout Standard
ANSI
Layout Standard
ANSI, ISO
Layout Ergonomics
Ortholinear
Layout Ergonomics
Normal
Layout Ergonomics
Normal
Knob Support
 
Knob Support
 
Knob Support
 
Display Support
 
Display Support
 
Display Support
 
Mac/Win Support
 
Mac/Win Support
 
Mac/Win Support
 
Multi-Media Keys
 
Multi-Media Keys
 
Multi-Media Keys
 
USB-C
 
USB-C
 
USB-C
 
USB passthrough
 
USB passthrough
 
USB passthrough
 
Connection
Bluetooth, 2.4 GHz, Wired, Wireless
Connection
Bluetooth, Wireless, Wired
Connection
Bluetooth, Wired, Wireless
Polling Rate
-
Polling Rate
1000 Hz
Polling Rate
1000 Hz
Battery capacity
-
Battery capacity
1000 mAh
Battery capacity
4000 mAh
Hall Effect Support
 
Hall Effect Support
 
Hall Effect Support
 
QMK Support
 
QMK Support
 
QMK Support
 
VIA Support
 
VIA Support
 
VIA Support
 
VIAL Support
 
VIAL Support
 
VIAL Support
 
N-Key Rollover
 
N-Key Rollover
 
N-Key Rollover
 
Rapid Trigger
 
Rapid Trigger
 
Rapid Trigger
 
Mount Style
Gasket Mount
Mount Style
Gasket Mount
Mount Style
Gasket Mount
Screw in Stabilizers
 
Screw in Stabilizers
 
Screw in Stabilizers
 
Sound Dampening
 
Sound Dampening
 
Sound Dampening
 
Backlight
 
Backlight
 
Backlight
 
Rgb, South-face
Case Colors
Case Colors
Case Colors
Case Material
Aluminum
Case Material
Polycarbonate, Brass, Aluminum
Case Material
Aluminum
Keycaps Material
-
Keycaps Material
-
Keycaps Material
PBT
Dimensions
-
Dimensions
40 x 250 x 120 mm
Dimensions
21 x 121 x 303 mm
Weight
-
Weight
700g
Weight
1351g
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Product Description

The NIUNIU KB40 Electrocapacitive is a 40% mechanical keyboard kit designed for hobbyists and enthusiasts who want a compact layout with electrocapacitive switch compatibility. It suits users who value a small footprint and the option to customize with both MX-style and electrocapacitive switches. The kit format requires assembly and some familiarity with keyboard building.

Key Features

  • Supports both MX-style and electrocapacitive switches, allowing users to choose between different typing feels and durability.
  • Hotswappable PCB options simplify switch replacement without soldering.
  • Multiple layout options including staggered and ortholinear, catering to various typing preferences.
  • Wireless models support 2.4GHz connection but require a separate dongle for wireless use.

Build Quality

  • Aluminum top and bottom frame provide a solid, stable base for typing.
  • Includes gasket tadpoles and O-rings, which help reduce typing noise and soften keypress impact.
  • Rubber feet improve desk grip and stability during use.
  • PCB and plate materials vary by model, with FR4 for wired and aluminum for wireless versions.

Connectivity

  • Available in wired and wireless versions, offering flexibility depending on user setup.
  • Wireless models require purchasing a separate 2.4GHz dongle to enable connection.
  • Battery included only with wireless models.

Trade-offs

  • As a kit, assembly is required, which may not suit users seeking a ready-to-use keyboard.
  • No foam or sound dampening materials included, so users wanting quieter typing must source these separately.
  • Wireless dongle sold separately, adding complexity for users wanting wireless functionality.
  • Unknown details on firmware and software customization options.

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