MicroBT Whatsminer M21S firmware

Official firmware versions matched to the exact ASIC model or manufacturer family. Local copies include SHA-256 checksums.

Firmware is hardware-specific. Match the exact model and control-board revision, back up settings, use stable power, test one miner first, and never interrupt an upgrade. A wrong image can make the controller unbootable.

Official manufacturer firmware

1 versions

Official family firmware Official source: WhatsMiner Firmware Download ↗

Version	Published / updated	Compatibility	Size	SHA-256	Download
20220919.15Whatsminer-M2x-all-20220919.15.bin	2023-02-19	M2x series	18.2 MB	`5d93927db6c3c086e0940e78c66a6151bc4cc943c2152a4b4b1b3b68763692e4`MD5: f09aa7604a399c14a5707fa3aed97d12	Download local verified copy ↓Official source ↗
Release notes: 1. Applicable mode 1.1 M21S, M20S, M21,etc; 1.2 High mode can not be supported; 1.3 Teaching video: https://youtu.be/L-gpDzD9YCU 2. New version highlights 2.1 Support Pool TLS safety transportation protocol; 2.2 If the miner firmware is before 2021, it is recommended to upgrade the firmware after SD-card flashing; 2.3 Strengthen the safety of firmware: device will reboot 2 times during upgrading,the version name will be end with"NeedUpgradeAgain" at 1st time，please wait for 2nd reboot, after that it will be changed to target version; 2.4 Fixing other bugs; 2.5 Online upgrading to version earlier than 20210602 is prohibit， suggest to match with tool whatsminertool-8.1.34 ; 2.6 The WhatsMiner API version is V2.0.5;

Verify the downloaded file with SHA-256 before uploading it to a miner.

Sources checked 14 September 2026