Upgrade Firmware

Learn how to upgrade here >

Current Version of Coldcard Firmware

Version 2.0.4

2019-05-13T1631-v2.0.4-coldcard.dfu built May 13, 2019.

Release Notes (v2.0.3 – 2.0.4)

Older Changes (2.0.0 – 2.0.2)

Older releases and their changes are listed here, the source code, and much more be found in our repository on github.

How to upgrade

Advanced: Verify Your Downloads

The release binaries may be verified using this clear-signed text file and GPG. The command is:

gpg --verify signatures.txt

Please look for signing key: 4589779ADFC14F3327534EA8A3A31BAD5A2A5B10

Don't forget to run SHA256 over the DFU files themselves, because that compares your actual file contents to what we signed.

Github.com is also protecting us because it verifies on all commits against the developer's public keys, and keeps a history of changes.


The upgrade menu allows you to load updated firmware onto the Coldcard.

advanced menu

The menu allows loading an upgrade file from a MicroSD card, but it can also be done using the command line tool, or from the Electrum plugin.

How to Upgrade

Show Version
Displays the version numbers that you have already.
From MicroSD
Select an upgrade file from MicroSD card and start the process.
Bless Firmware
Mark the contents of flash memory as "approved" and light the green "Genuine" light.

Upgrade Files

You need a DFU file for upgrades. It's about 690k in size and should have the extension .dfu.

The latest firmware will always be available in Github:


All upgrade files must be signed by a Coinkite Inc. approved key, or the Coldcard will refuse to load and run them.

Bless Firmware

This command is not typically needed, but can be used to set the genuine/caution lights to green. Note that only the main PIN holder can do this. A normal firmware upgrade sequence does not require this action, but if the unit is powered down between installing the upgrade and the first successful login, then the light will be red and stays red until this command is used.

Downgrade Protection

In general, it may not be possible to downgrade (return to an older release). Some releases will set a "high water mark" so the bootloader that will block any downgrade to earlier versions. We will do this if a bug or security problem with an obsolete release is identifed.