Article · Wikipedia archive · Last revised May 31, 2026

Odin (firmware flashing software)

Odin is a utility software program developed and used by Samsung internally which is used to communicate with Samsung devices in Odin mode through the thor protocol. It can be used to flash a custom recovery firmware image to a Samsung Android device. Odin is also used for unbricking certain Android devices. Odin is the Samsung proprietary alternative to Fastboot.

Last revised
May 31, 2026
Read time
≈ 3 min
Length
712 w
Citations
19
Source
Wikipedia ↗
Odin
DeveloperSamsung
Stable release
Windowv3 – 3.14.11 / February 16, 2020 (2020-02-16)
Linuxv4 1.2.1-dc05e3ea2 / June 3, 2022 (2022-06-03)
Operating system(v3) Windows (v4) Linux
Available inEnglish

Odin is a utility software program developed and used by Samsung internally which is used to communicate with Samsung devices in Odin mode (also called download mode) through the thor protocol.3 It can be used to flash a custom recovery firmware image (as opposed to the stock recovery firmware image) to a Samsung Android device. Odin is also used for unbricking certain Android devices.4 Odin is the Samsung proprietary alternative to Fastboot.

There is no account of Samsung ever having officially openly released Odin,5 though it is mentioned in the developer documents for Samsung Knox SDK6 and some documents even instruct users to use Odin.7 Some other docs on Knox SDK reference "engineering firmware",89 which presumably can be a part of the Knox SDK along with Odin. Publicly available binaries are believed to be the result of leaks. The tool is not intended for end-users, but for Samsung's own personnel and approved repair centers.10

Usage

Although none of the publicly available downloads are authorized by Samsung itself, XDA-Developers consider the files offered on their Forum the safest option. For the usage of Odin, the phone needs to be in Download mode. For this, some key combination need to be pressed, such as Power + Volume Down + Home, or Power + Volume Down + Bixby, or connect to a computer while performing the Volume Up + Volume Down key combination.11

In 2026, Samsung started requiring to enable the Maintenance mode in the system settings before it is possible to access download mode.12

The thor protocol that Odin implements is used in many Samsung devices, including in some devices co-developed by Google and Samsung like the Galaxy Nexus.13 There is also an implementation of the thor protocol in Das U-Boot3.

Heimdall

Graphical user interface for Heimdall running on Ubuntu source ↗

Heimdall is a free/libre/open-source, cross-platform replacement for Odin which is based on libusb.145 Heimdall can be used on Windows, Linux, and Mac.15 The name Heimdall, like Odin, is an allusion to Norse mythology; both Odin and Heimdall are among the deities of the Norse pantheon16. It can be used either through the command line17 or with its graphical user interface.

References

References

  1. "Patched Odin 3.13.1". XDA Forums. 13 March 2018. Retrieved 20 April 2026.
  2. "OFFICIAL Samsung Odin v4 1.2.1-dc05e3ea - For Linux". XDA Forums. 3 June 2022. Retrieved 20 April 2026.
  3. "Convert CONFIG_CMD_THOR_DOWNLOAD to Kconfig". Das U-Boot. 8 November 2017. Retrieved 17 December 2025.
  4. "Odin Download: Samsung Firmware Flash Tool". Magisk ZIP. 9 December 2023. Retrieved 13 December 2023.
  5. Drake, Joshua J. (2014). Android hacker's handbook. Zach Lanier, Collin Mulliner, Pau Oliva, Stephen A. Ridley, Georg Wicherski. Indianapolis, IN: Wiley. p. 488. ISBN 978-1-118-60861-6. OCLC 875820167.
  6. "Knox Glossary of Terms and Acronyms" (PDF). Samsung.com. Santa Clara, California: Samsung. 17 October 2013. Archived from the original (PDF) on 30 October 2017. Retrieved 4 July 2019.
  7. "How Can I Change or Download the Device Firmware?". Samsung Enterprise Alliance Program. Archived from the original on 13 June 2018.
  8. "How Can I Check If My Device Firmware is an Engineering or Commercial Build?". Samsung Enterprise Alliance Program. Archived from the original on 13 June 2018.
  9. "How Can I Make My App Work Properly on a Device with Engineering Firmware?". Samsung Enterprise Alliance Program. Archived from the original on 13 June 2018.
  10. Crider, Michael (5 February 2018). "How to Manually Update Your Samsung Phone with Odin". How-To Geek. Retrieved 13 May 2020.
  11. Dumitru, Bogdan. "Boot any Samsung Devices into Download Mode". Odin. Archived from the original on 2 December 2021. Retrieved 11 September 2021.
  12. "Samsung's latest update is a serious gut punch to Galaxy power users (Update)". Android Authority. 12 March 2026. Retrieved 18 March 2026.
  13. "[Q] [Galaxy Nexus] broken recovery mode, is there ROM package for Heimdall?". XDA Developers forum. Retrieved 17 December 2025.
  14. Dobell, Benjamin, Benjamin-Dobell/Heimdall, Github, retrieved 20 April 2026
  15. Shukla, Rakesh (9 April 2023). "Flash Samsung Firmware with Heimdall & JOdin3 on Mac". Technastic. Retrieved 21 September 2024.
  16. "Heimdall". Glass Echidna. Retrieved 15 December 2021.
  17. "Install LineageOS on Samsung Galaxy S III (International)". LineageOS. Retrieved 17 December 2025.