Smlight SLZB-MR4 vs Sonoff Dongle Lite MG21

Updated March 2026

Data from Amazon and official Smlight and Sonoff sites.

2026 verdict

For 2026, Smlight SLZB-MR4 is the stronger overall choice. It separates itself most clearly on power, connectivity, and antenna gain, while still looking better on dual network and bluetooth proxy. Sonoff Dongle Lite MG21 still makes sense if its specific feature mix is your priority, but most buyers should still lean toward Smlight SLZB-MR4. That makes Smlight SLZB-MR4 the clearer recommendation in 2026.

Winner

Smlight

Smlight SLZB-MR4

Price unavailable right now

BUY NOW

Sonoff

Sonoff Dongle Lite MG21

$19.90

BUY NOW

Feature	Smlight SLZB-MR4	Sonoff Dongle Lite MG21	Winner
Power	USB, PoE	USB	Smlight SLZB-MR4
Connectivity	USB, Ethernet, 2.4 GHz Wifi	USB	Smlight SLZB-MR4
Antenna Gain	+5dBi	+3dBi	Smlight SLZB-MR4
Dual Network	YES	NO	Smlight SLZB-MR4
Bluetooth Proxy	YES	NO	Smlight SLZB-MR4
Zigbee Chip Model	EFR32MG26 / CC2674P10	EFR32MG21	Different strengths
Amplifier Gain	+20dB	+20 dBm	Different strengths
Warranty	1 year	1 year	Tie
Zigbee Router	YES	YES	Tie
Z-Wave Controller	NO	NO	Tie
Thread Border Router	YES	YES	Tie
Matter Bridge	NO	NO	Tie

Winner

Smlight

Smlight SLZB-MR4

Price unavailable right now

BUY NOW

+ Power: USB, PoE
+ Connectivity: USB, Ethernet, 2.4 GHz Wifi
+ Antenna Gain: +5dBi

Sonoff

Sonoff Dongle Lite MG21

$19.90

BUY NOW

- Power: USB vs USB, PoE
- Connectivity: USB vs USB, Ethernet, 2.4 GHz Wifi

Frequently Asked Questions (FAQ)

Which is better overall: Smlight SLZB-MR4 or Sonoff Dongle Lite MG21?: Smlight SLZB-MR4 has the stronger overall profile in this comparison, especially for power, connectivity, and antenna gain.
What is the biggest difference between Smlight SLZB-MR4 and Sonoff Dongle Lite MG21?: Power is one of the clearest differences: Smlight SLZB-MR4 lists USB, PoE, while Sonoff Dongle Lite MG21 lists USB.
Who should buy Smlight SLZB-MR4?: Choose Smlight SLZB-MR4 if your priority is power and connectivity and that matters more than the competing advantages.
Who should buy Sonoff Dongle Lite MG21?: Choose Sonoff Dongle Lite MG21 if your priority is its specific strengths and that matters more than power.

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