Existing WiFi mesh networks are usually implemented on high-end or PC grade platforms. However, the open source community has been recently developing a unique mesh network library targeted for the low-cost and resource limited ESP8266 platform. The so called painlessMesh library enables two or more ESP8266 modules to self-configure and to form a WiFi mesh network. This might open up new potential for the ESP8266 to be used in wider application areas. The library is in an early development stage and not much is known about its performance. Therefore, this paper aims to evaluate to what extent the ESP8266 painlessMesh network can perform, in terms of one-way delay and data rate. Measurements showed that a 2-node network has a delay of 2.49 ms. A network consisting of higher number of nodes tends to have an increased network delay even for the same hop distance. Meanwhile, data rate measurements showed that for the case of 10-byte payload a node can receive up to 461 messages/sec. Whereas for payload of 4400 bytes, the node can receive up to 28 messages/sec. Furthermore, it can be reported that payload greater than 4400 bytes starts causing incomplete and erroneous messages.