Number devices on home WiFi router ? (MQTT)


I have a new setup of openHAB using MQTT and mostly SONOFF items and ESP8266 sensors.

My question is how many devices will my wifi router handle? Currently my router is the supplied ADSL2 router from my isp (UK). I want to get a better third party router later but for now this one is new (2mths old) and working well. Its based on the SAGEMCOM FAST 5364 router i believe, although with a very stripped down ISP firmware!

I currently have just 11 wifi devices connected. But i just ordered 10 more SONOFF devices and a dozen new ESP8266 boards to build.

Now im worried that 30+ devices may be an issue on my router?

Yes, you are right to start worrying.
It will be a problem. Most isp supplied routers will handle 20-30 WiFi connections.
I suggest a beefier router or a professional access point
You can find second hand ones real cheap one ebay.
Mostly they are old access points taken from shops and warehouses refurbisments. They’ll handle only 2.4ghz WiFi but that’s what the ESP8266 uses anyway and they can handle a lot on connections.