How to determine flash size of NodeMCU?

Just bought a couple of NodeMCU from vendor on AliExpress. They were advertised as "v2" and having 4M flash.

How can I verify the flash size? The board says "Ver 0.1", but don't know if that means anything.

You have basically two options: install a firmware (NodeMCU, Arduino, etc.) and use their functions or extract the flash ID and look it up.

Install NodeMCU

• Build and flash the NodeMCU firmware.
• Run print(node.flashsize())

Chip ID

• install esptool.py
• run esptool.py -p <serial-port> flash_id (gives you a hex manufacturer & chip ID)
• look up the chip in https://review.coreboot.org/plugins/gitiles/flashrom/+/refs/heads/master/include/flashchips.h