MicroPython - Python for microcontrollers

ESP8266

Vendor: Espressif

Features: External Flash, WiFi

Source on GitHub: esp8266/ESP8266_GENERIC

More info: Website

The following are daily builds of the ESP8266 firmware. This will work on boards with at least 2MiB of flash. They have the latest features and bug fixes, WebREPL is not automatically started, and debugging is enabled by default.

For boards with 1MiB or 512kiB of flash, two variants are provided with reduced functionality. The 1MiB variant removes asyncio and FAT-filesystem support as well as some modules from micropython-lib. The 512kiB variant further removes all filesystem support, as well as framebuffer support, some Python language features, and has less detailed error messages.

Boards with more than 4MiB of flash (e.g. 8MiB or 16MiB) need an extra step to write the esp_init_data RF calibration data, otherwise WiFi will not start. See Boards with more than 4MB of flash in the tutorial for details.

Note: v1.12-334 and newer (including v1.13) require an ESP8266 module with 2MiB of flash or more, and use littlefs as the filesystem by default. When upgrading from older firmware please backup your files first, and either erase all flash before upgrading, or after upgrading execute vfs.VfsLfs2.mkfs(bdev).

Installation instructions

Program your board using the esptool.py program as described the tutorial.

Firmware

Releases

v1.28.0 (2026-04-06) .bin / [.elf] / [.map] / [Release notes] (latest)

v1.27.0 (2025-12-09) .bin / [.elf and .map] / [Release notes]

v1.26.1 (2025-09-11) .bin / [.elf and .map] / [Release notes]

v1.26.0 (2025-08-09) .bin / [.elf and .map] / [Release notes]

v1.25.0 (2025-04-15) .bin / [.elf and .map] / [Release notes]

v1.24.1 (2024-11-29) .bin / [.elf and .map] / [Release notes]

v1.24.0 (2024-10-25) .bin / [.elf and .map] / [Release notes]

v1.23.0 (2024-06-02) .bin / [.elf and .map] / [Release notes]

v1.22.2 (2024-02-22) .bin / [.elf and .map] / [Release notes]

v1.22.1 (2024-01-05) .bin / [.elf and .map] / [Release notes]

v1.22.0 (2023-12-27) .bin / [.elf and .map] / [Release notes]

v1.21.0 (2023-10-05) .bin / [.elf and .map] / [Release notes]

v1.20.0 (2023-04-26) .bin / [.elf and .map] / [Release notes]

v1.19.1 (2022-06-18) .bin / [.elf and .map] / [Release notes]

v1.18 (2022-01-17) .bin / [.elf and .map] / [Release notes]

v1.17 (2021-09-02) .bin / [.elf and .map] / [Release notes]

v1.16 (2021-06-18) .bin / [.elf and .map] / [Release notes]

v1.15 (2021-04-18) .bin / [.elf and .map] / [Release notes]

v1.14 (2021-02-02) .bin / [.elf and .map] / [Release notes]

v1.13 (2020-09-11) .bin / [.elf and .map] / [Release notes]

v1.12 (2019-12-20) .bin / [.elf and .map] / [Release notes]

v1.11 (2019-05-29) .bin / [.elf and .map] / [Release notes]

v1.10 (2019-01-25) .bin / [.elf and .map] / [Release notes]

v1.9.4 (2018-05-11) .bin / [.elf and .map] / [Release notes]

v1.9.3 (2017-11-01) .bin / [.elf and .map] / [Release notes]

v1.9.2 (2017-08-23) .bin / [.elf and .map] / [Release notes]

v1.9.1 (2017-06-12) .bin / [.elf and .map] / [Release notes]

v1.9 (2017-05-26) .bin / [.elf and .map] / [Release notes]

v1.8.7 (2017-01-08) .bin / [.elf and .map] / [Release notes]

Preview builds

These are automatic builds of the development branch for the next release.

v1.29.0-preview.707.g1827631282 (2026-08-13) .bin / [.elf] / [.map]

v1.29.0-preview.697.g2aa39667b4 (2026-08-12) .bin / [.elf] / [.map]

v1.29.0-preview.678.g5f2181f938 (2026-08-07) .bin / [.elf] / [.map]

v1.29.0-preview.673.g06bcfd5b74 (2026-08-02) .bin / [.elf] / [.map]

Firmware (1MiB flash)