MetaMask 3 Migration Guide

Backing up loose accounts in MetaMask.

This article discusses a very rare issue after the jump to MetaMask 3.0.0+. Most users will not be affected, but may be interested to know about how MetaMask accounts are managed.

MetaMask has been growing a lot lately, and one of our latest efforts has been to begin adjusting to support multiple account types.
 
 One of the changes we made in this transition was to finally fix a small outstanding bug in the way accounts were generated. This means that after we release MetaMask version 3.0.0, a small number of users will have seed phrases that now generate different accounts.

Fortunately for these users, we’ve gone to some lengths to ensure a smooth transition.

You Still Have Your Old Accounts!

It took some work, but for a limited time, we are still migrating old vaults into the new format as well as recovering the affected accounts. If your vault was affected, you’ll see this screen appear in the near future:

In fact, you may have found yourself at this article because of the link in this message. If you see this message, don’t fear, while some of your accounts will not be restored with your seed phrase in the future, we’ve imported them for now, and labeled them LOOSE, like Account 4 here:

The Rescued Accounts Are Not Backed Up

A lot of the stability in MetaMask comes from your trusty seed phrase. With it, you can always re-generate all your accounts on any machine you like, in the same order, every time. This is cool technique called HD Trees, or Hierarchical Derivation Trees, and has some history in Bitcoin.

While we were able to recover the old accounts, your seed phrase will no longer recover those accounts, and so if you have accounts like this, you should immediately export them and back them up, or maybe just transfer their balances to accounts that are part of your HD Tree.

You can export a MetaMask account using the key button on the main account panel:

Sorry if you hit this issue, but rest assured that we made this change so that we would be more compatible with the wider ecosystem, so it should be a good change in the long term.
 
 If you’re curious about what caused this bug, you can read a good write-up about it here.