How to detect the flash size of ESP8266 module?

• Install latest esptool from GitHub or with pip
• Wire ESP8266 module with a programmer
• Run command

esptool.py flash_id

You should get some information about the flash of ESP8266 module

esptool.py v2.6-beta1
Found 2 serial ports
Serial port /dev/cu.SLAB_USBtoUART
Connecting........_
Detecting chip type... ESP8266
Chip is ESP8266EX
Features: WiFi
MAC: 18:fe:34:9f:5a:0a
Uploading stub...
Running stub...
Stub running...
Manufacturer: c8
Device: 4013
Detected flash size: 512KB
Hard resetting via RTS pin...

• So the flash size is 512KB