Antminer S21 & T21 firmware — free download
Free AsicMiner firmware for the Antminer S21, S21 Pro, S21 XP, S21+ (air, hydro and immersion) and T21: guided autotuning, per-board monitoring and a clean rollback path. Pick the build for your control board below.
- Up to +20% hashrate
- Up to −25% power
- Live monitoring & autotuning
- Free & reversible
Choose your Antminer S21 / T21 build
Every package is tied to a specific control board and storage target — match both before flashing. Not sure which control board you have? →
Firmware for Antminer S21
Firmware packages for Antminer S21.
1 package
Firmware for Antminer S21
Firmware packages for Antminer S21.
Fits
Antminer S21 200T – Antminer S21 – 151T
Antminer S21 200T – Antminer S21 – 175T
Antminer S21 200T – Antminer S21 – 188T
Antminer S21 200T – Antminer S21 – 195T
Antminer S21 200T
Recovery support
Use stock or SD recovery files only when you need to restore the miner or return to factory firmware.
| Version | Status | Controller | Storage | Download |
|---|---|---|---|---|
| v1.3.6 | Stable | Amlogic | NAND / internal flash |
Firmware for Antminer S21 Hydro
Firmware packages for Antminer S21 Hydro.
1 package
Firmware for Antminer S21 Hydro
Firmware packages for Antminer S21 Hydro.
Recovery support
Use stock or SD recovery files only when you need to restore the miner or return to factory firmware.
| Version | Status | Controller | Storage | Download |
|---|---|---|---|---|
| v1.3.6 | Stable | Xilinx | NAND / internal flash |
Firmware for Antminer S21 Immersion
Firmware packages for Antminer S21 Immersion.
1 package
Firmware for Antminer S21 Immersion
Firmware packages for Antminer S21 Immersion.
Recovery support
Use stock or SD recovery files only when you need to restore the miner or return to factory firmware.
| Version | Status | Controller | Storage | Download |
|---|---|---|---|---|
| v1.3.6 | Stable | Amlogic | NAND / internal flash |
Firmware for Antminer S21 Plus
Firmware packages for Antminer S21 Plus.
1 package
Firmware for Antminer S21 Plus
Firmware packages for Antminer S21 Plus.
Recovery support
Use stock or SD recovery files only when you need to restore the miner or return to factory firmware.
| Version | Status | Controller | Storage | Download |
|---|---|---|---|---|
| v1.3.6 | Stable | Amlogic | NAND / internal flash |
Firmware for Antminer S21 Plus Hydro
Firmware packages for Antminer S21 Plus Hydro.
2 packages
Firmware for Antminer S21 Plus Hydro
Firmware packages for Antminer S21 Plus Hydro.
Recovery support
Use stock or SD recovery files only when you need to restore the miner or return to factory firmware.
| Version | Status | Controller | Storage | Download |
|---|---|---|---|---|
| v1.3.6 | Stable | CVitek | NAND / internal flash | |
| v1.3.6 | Stable | Xilinx | NAND / internal flash |
Firmware for Antminer S21 Pro
Firmware packages for Antminer S21 Pro.
1 package
Firmware for Antminer S21 Pro
Firmware packages for Antminer S21 Pro.
Recovery support
Use stock or SD recovery files only when you need to restore the miner or return to factory firmware.
| Version | Status | Controller | Storage | Download |
|---|---|---|---|---|
| v1.3.6 | Stable | Amlogic | NAND / internal flash |
Firmware for Antminer S21 Pro Plus
Firmware packages for Antminer S21 Pro Plus.
1 package
Firmware for Antminer S21 Pro Plus
Firmware packages for Antminer S21 Pro Plus.
Recovery support
Use stock or SD recovery files only when you need to restore the miner or return to factory firmware.
| Version | Status | Controller | Storage | Download |
|---|---|---|---|---|
| v1.3.6 | Stable | Amlogic | NAND / internal flash |
Firmware for Antminer S21 XP
Firmware packages for Antminer S21 XP.
1 package
Firmware for Antminer S21 XP
Firmware packages for Antminer S21 XP.
Fits
Antminer S21 XP 270T
Recovery support
Use stock or SD recovery files only when you need to restore the miner or return to factory firmware.
| Version | Status | Controller | Storage | Download |
|---|---|---|---|---|
| v1.3.6 | Stable | Amlogic | NAND / internal flash |
Firmware for Antminer S21 XP Hydro
Firmware packages for Antminer S21 XP Hydro.
1 package
Firmware for Antminer S21 XP Hydro
Firmware packages for Antminer S21 XP Hydro.
Recovery support
Use stock or SD recovery files only when you need to restore the miner or return to factory firmware.
| Version | Status | Controller | Storage | Download |
|---|---|---|---|---|
| v1.3.6 | Stable | Xilinx | NAND / internal flash |
Firmware for Antminer S21 XP Immersion
Firmware packages for Antminer S21 XP Immersion.
1 package
Firmware for Antminer S21 XP Immersion
Firmware packages for Antminer S21 XP Immersion.
Recovery support
Use stock or SD recovery files only when you need to restore the miner or return to factory firmware.
| Version | Status | Controller | Storage | Download |
|---|---|---|---|---|
| v1.3.6 | Stable | Amlogic | NAND / internal flash |
Firmware for Antminer S21e Hydro
Firmware packages for Antminer S21e Hydro.
2 packages
Firmware for Antminer S21e Hydro
Firmware packages for Antminer S21e Hydro.
Recovery support
Use stock or SD recovery files only when you need to restore the miner or return to factory firmware.
| Version | Status | Controller | Storage | Download |
|---|---|---|---|---|
| v1.3.6 | Stable | Amlogic | NAND / internal flash | |
| v1.3.6 | Stable | Xilinx | NAND / internal flash |
Firmware for Antminer S21e XP Hydro
Firmware packages for Antminer S21e XP Hydro.
1 package
Firmware for Antminer S21e XP Hydro
Firmware packages for Antminer S21e XP Hydro.
Recovery support
Use stock or SD recovery files only when you need to restore the miner or return to factory firmware.
| Version | Status | Controller | Storage | Download |
|---|---|---|---|---|
| v1.3.6 | Stable | Xilinx | NAND / internal flash |
Firmware for Antminer T21
Firmware packages for Antminer T21.
3 packages
Firmware for Antminer T21
Firmware packages for Antminer T21.
Recovery support
Use stock or SD recovery files only when you need to restore the miner or return to factory firmware.
| Version | Status | Controller | Storage | Download |
|---|---|---|---|---|
| v1.3.6 | Stable | Amlogic | NAND / internal flash | |
| v1.3.6 | Stable | CVitek | NAND / internal flash | |
| v1.3.6 | Stable | Xilinx | NAND / internal flash |
Firmware for Antminer U3s21exph
Firmware packages for Antminer U3s21exph.
1 package
Firmware for Antminer U3s21exph
Firmware packages for Antminer U3s21exph.
Recovery support
Use stock or SD recovery files only when you need to restore the miner or return to factory firmware.
| Version | Status | Controller | Storage | Download |
|---|---|---|---|---|
| v1.3.6 | Stable | Xilinx | NAND / internal flash |
Install in three steps
From download to a tuned miner — usually under 15 minutes.
-
1
Pick your build above
Match your exact model, control board and storage type.
-
2
Flash the package
Install fresh or update in place — the guide covers both paths.
-
3
Pick a profile & tune
Efficiency, balanced or max output — autotune does the rest.
Antminer S21 / T21 firmware — frequently asked
Is the Antminer S21 / T21 firmware really free?
Yes — every package is free to download. The firmware runs a small, transparent dev fee on hashrate, in line with the rest of the industry.
Which Antminer S21 / T21 models are supported?
Every model family listed on this page has verified install and update packages. Open a family to see the exact builds for your control board and storage type.
How do I know which control board my miner has?
Open the miner and check the controller module label, or follow the identification steps in our installation guide — Amlogic, BeagleBone, CVitek and Xilinx boards each have a matching package.
Can I go back to stock firmware?
Yes. Installation is staged with power-limit protection and every model keeps a documented rollback path — you can return to a previous build at any time.
Looking for another model?
Need a hand flashing your Antminer S21 / T21?
Our engineers install and tune remotely or guide you step by step — free for firmware users.
