This product has shipping restrictions, so it might have limited shipping options or cannot be shipped to the following countries:
Creative Commons images are CC BY 2.0
There is an almost limitless fountain of information available for the ESP8266, all of which has been provided by amazing community support. In the Documents section below you will find many resources to aid you in using the ESP8266, even instructions on how to transforming this module into an IoT (Internet of Things) solution!
Note: The ESP8266 Module is not capable of 5-3V logic shifting and will require an external Logic Level Converter. Please do not power it directly from your 5V dev board.
Note: This new version of the ESP8266 WiFi Module has increased the flash disk size from 512k to 1MB.
The ESP8266 is a low-cost Wi-Fi chip with full TCP/IP stack and MCU (microcontroller unit) capability produced by Shanghai-based Chinese manufacturer, Espressif Systems. 
The ESP8285 is an ESP8266 with 1 MiB of built-in flash, allowing for single-chip devices capable of connecting to Wi-Fi. 
The successor to these microcontroller chips is the ESP32.
† Both the CPU and flash clock speeds can be doubled by overclocking on some devices. CPU can be run at 160 MHz and flash can be sped up from 40 MHz to 80 MHz. [ citation needed ] Success varies chip to chip. [ citation needed ]
In late October 2014, Espressif Systems released a software development kit (SDK) that allowed the chip to be programmed, removing the need for a separate microcontroller.  Since then, there have been many official SDK releases from Espressif; Espressif maintains two versions of the SDK – one that is based on FreeRTOS and the other based on callbacks.