Live nowPrime Day 2026October 6 to 7, 2026Starts in09d13h35m04sSee the deals
Plugs · Head to head

Sonoff S31 WiFi Smart Plug vs Sonoff WiFi Smart Plug S40

Full Smart Plugs comparison in 2026

Updated September 2026
Data from Amazon and official Sonoff site.
2026 verdict
In this 2026 Sonoff WiFi Smart Plug S40 vs Sonoff S31 WiFi Smart Plug comparison, Sonoff WiFi Smart Plug S40 comes out ahead thanks to rating and connectivity.
Sonoff WiFi Smart Plug S40
Winner
Sonoff WiFi Smart Plug S40
$10.90
Buy on Amazon USACheck price
What pushes it ahead is rating and connectivity, and its broader overall balance keeps the advantage from looking narrow. Choose Sonoff S31 WiFi Smart Plug only if its specific feature mix matters more to you than the broader advantage from Sonoff WiFi Smart Plug S40. That makes Sonoff WiFi Smart Plug S40 the clearer recommendation in 2026.
vs
Price alerts

Plug prices change while you decide

We check the price of every Plug in the catalog daily and email you the drops, whichever one you pick.

Smart home deals and news, straight to your inbox

Price drops, new releases and the smart home news worth knowing.

No spam. Unsubscribe in one click.

Your subscription could not be saved. Please try again.
Please enter a valid email address.
Your subscription has been successful.
FeatureSonoff S31 WiFi Smart PlugSonoff WiFi Smart Plug S40Winner
Rating4.14.2Sonoff WiFi Smart Plug S40
Connectivity2.4 GHz WiFi2.4 GHz WiFi, BluetoothSonoff WiFi Smart Plug S40
Price$10.90$10.90Tie
Weather ResistanceNONOTie
Plug FormatType BType BTie
Maximum Load Power1800W1800WTie
Energy MonitoringYESYESTie
IntegrationsGoogle Home, Alexa, Apple HomeKit, Samsung SmartThings, Home Assistant, MatterGoogle Home, Alexa, Apple HomeKit, Samsung SmartThings, Home Assistant, MatterTie
On/Off ButtonYESYESTie
Zibgee RouterNONOTie

Price history compared

Every price change of both, in the same store, so the gap between the two lines is what one costs more than the other.

  • Sonoff S31 WiFi Smart Plug
  • Sonoff WiFi Smart Plug S40

Loading price history...

Frequently Asked Questions

Which is better overall: Sonoff S31 WiFi Smart Plug or Sonoff WiFi Smart Plug S40?

Sonoff WiFi Smart Plug S40 has the stronger overall profile in this comparison, especially for rating and connectivity.

What is the biggest difference between Sonoff S31 WiFi Smart Plug and Sonoff WiFi Smart Plug S40?

Rating is one of the clearest differences: Sonoff S31 WiFi Smart Plug lists 4.1, while Sonoff WiFi Smart Plug S40 lists 4.2.

Which one looks better on price?

Sonoff S31 WiFi Smart Plug is listed at $10.90, while Sonoff WiFi Smart Plug S40 is listed at $10.90. Tie.

Who should buy Sonoff S31 WiFi Smart Plug?

Choose Sonoff S31 WiFi Smart Plug if your priority is its specific strengths and that matters more than rating.

Who should buy Sonoff WiFi Smart Plug S40?

Choose Sonoff WiFi Smart Plug S40 if your priority is rating and connectivity and that matters more than the competing advantages.

Full comparison table

Compare all 36 Plugs side by side

You are looking at two of them. The full table lines up all Plugs in the catalog with the same specs, so you can filter by what you need and sort by price or rating.

  • 36 Plugs
  • 31 specs compared
  • 28 filters
Open the full comparison
More Plugs

Top Plugs to compare next

36 smart plugs from 14 brands compared: Sonoff, Meross, Aqara, Shelly and more. Max load, energy metering, protocols and local control.

All Plugs
Sonoff

More Sonoff products

A sharper look at other Sonoff products worth comparing.

Explore Sonoff
Independent · Not sponsoredBrands never pay for placement or rankings. Affiliate commissions never influence our comparisons.
© 2026 Smart Home Compared
Search