I need to determine the flash size of my ESP8266 on my NodeMCU module in order to flash the AT firmware onto the board. Apparently different boards come with differently-sized flash memories. Can anyone tell me the easiest way to find the flash size?

  • By reading the manual for your NodeMCU. Which version is it?
    – Majenko
    May 27 '16 at 16:57
  • It's Version 1.0
    – Sumanth
    May 27 '16 at 18:32
  • The version 1.0 uses the ESP-12E which has 4MB flash.
    – Majenko
    May 27 '16 at 18:36
  • esptool.py -p COM5 -c esp8266 flash_id (you can find esptool inside ESP-IDF SDK components/esptool_py)
    – rustyx
    Jul 7 at 20:26

Arduino's ESP8266 support includes an example sketch called CheckFlashConfig. This probes the board, and prints the flash memory size.


The easiest way (windows at least) is to use Espressif's flash download tool - don't select anything to flash to the device, select the appropriate com port, click start, and the details of the device will appear in the Detected Info window

Not the answer you're looking for? Browse other questions tagged or ask your own question.