Compare Jamesdonkey RS2 4.0 vs Keychron K4 Ultra Differences Side by Side

Explore the comprehensive side-by-side comparison of the Jamesdonkey RS2 4.0 and Keychron K4 Ultra and view their biggest differences. The detailed comparison table allows you to see all the essential features, specifications, and benefits of each keyboard at a glance. Whether you're looking for performance, value, or specific functionalities, this comparison tool helps you make an informed decision.

Model
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Rating	0.0 stars (0 reviews)	5.0 stars (1 reviews)
Purchase Options
Main differences	Released in 2024 Has Linear switch options Comes with a knob Supports QMK firmware Uses a Gasket Mount mounting style Weighs about 1150 g Sized at 34 x 405 x 138 mm Made with a Aluminum case Offers Yes, Rgb RGB lighting	Released in 2026 Has Linear, Tactile, Clicky switch options Features N-key rollover Includes screw-in stabilizers Uses a Plate Mount mounting style Runs at a 8000 Hz polling rate Weighs about 1241 g Sized at 31 x 391 x 140 mm Made with a ABS case Offers Yes, Rgb, White, South-face, Rgb South-face, White South-face RGB lighting
Score	Scores Performance: 58.1 Build Quality: 71 Productivity: 93.1 Customizability: 82.6 Portability: 53.5	Scores Performance: 88.1 Build Quality: 63.5 Productivity: 86.5 Customizability: 75.2 Portability: 56.9
Name	Name Jamesdonkey RS2 4.0	Name Keychron K4 Ultra
Release year	Release year 2024	Release year 2026
Switch Options	Switch Options Linear	Switch Options Linear, Tactile, Clicky
Profile	Profile Normal Profile	Profile Normal Profile
Hot Swappable	Hot Swappable	Hot Swappable
Layout Size	Layout Size 96%, 95%	Layout Size 96%
Layout Standard	Layout Standard ANSI	Layout Standard ANSI
Layout Ergonomics	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	Connection Bluetooth, 2.4 GHz, Wired, Wireless	Connection Bluetooth, 2.4 GHz, Wired, Wireless
Polling Rate	Polling Rate -	Polling Rate 8000 Hz
Battery capacity	Battery capacity 4000 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	Mount Style Gasket Mount	Mount Style Plate Mount
Screw in Stabilizers	Screw in Stabilizers	Screw in Stabilizers
Sound Dampening	Sound Dampening	Sound Dampening
Backlight	Backlight Rgb	Backlight Rgb, White, South-face, White South-face
Case Colors	Case Colors	Case Colors
Case Material	Case Material Aluminum	Case Material ABS
Keycaps Material	Keycaps Material PBT	Keycaps Material PBT
Dimensions	Dimensions 34 x 405 x 138 mm	Dimensions 31 x 391 x 140 mm
Weight	Weight 1150g	Weight 1241g