esptool.py

TLDR

Flash firmware to ESP board

$ esptool.py --port [/dev/ttyUSB0] write_flash 0x0 [firmware.bin]

Read chip info

$ esptool.py --port [/dev/ttyUSB0] chip_id

Erase flash

$ esptool.py --port [/dev/ttyUSB0] erase_flash

Read flash to file

$ esptool.py --port [/dev/ttyUSB0] read_flash 0x0 0x100000 [backup.bin]

Verify flash contents

$ esptool.py --port [/dev/ttyUSB0] verify_flash 0x0 [firmware.bin]

Set baud rate

$ esptool.py --port [/dev/ttyUSB0] --baud [921600] write_flash 0x0 [firmware.bin]

SYNOPSIS

esptool.py [options] command [args]

esptool.py is the official flashing tool for Espressif ESP8266 and ESP32 microcontrollers. It communicates over serial to program firmware, read/write flash, and manage the boot process.
The tool handles bootloader communication, flash layout, and various chip-specific requirements. It supports multiple flash sizes, frequencies, and modes.
esptool.py is essential for ESP development, used by Arduino IDE, PlatformIO, and ESP-IDF for firmware deployment.

PARAMETERS

COMMAND

Operation: writeflash, readflash, eraseflash, chipid, etc.

--port PORT

Serial port device.

--baud RATE

Serial baud rate.

write_flash ADDR FILE

Write binary to flash at address.

read_flash ADDR SIZE FILE

Read flash to file.

erase_flash

Erase entire flash.

chip_id

Read chip ID.

--help

Display help information.

CAVEATS

Requires serial driver for USB adapter. Boot mode may need manual GPIO control. Flash addresses are chip-specific. Baud rate affects reliability vs speed.

HISTORY

esptool.py was developed by Espressif Systems as the official tool for their ESP8266 and ESP32 series of WiFi/Bluetooth microcontrollers, widely used in IoT projects.