Moving your 2FA codes to a new computer

With Never Lose Codes, moving to a new computer takes two things: your newest backup file and your recovery key. Here's the whole process, plus what to do if the old computer is already gone.

What you need

A backup file. Never Lose Codes writes encrypted backups to Downloads/NeverLoseCodes on your old computer, automatically, after every change.
Your recovery key. The 26-character key shown once when you set up. It's the only thing that opens a backup file. What a recovery key is explains it.

Your app password, if you set one, isn't needed for this. Backups open with the recovery key alone.

If you still have the old computer

On the old computer, open Never Lose Codes, go to Shield and click Back up now. This makes sure the newest file has every account.
Open Downloads/NeverLoseCodes and copy the newest file to a USB stick, or send it to yourself. It's encrypted, so it's safe to move, but keep it away from your recovery key.
Make sure you have your recovery key. If you can't find it, make a new one in Settings before you leave the old computer, then click Back up now again. New backups use the new key; older files still need the old one.
On the new computer, install Never Lose Codes in Chrome.
On the setup screen, choose I have a backup file, pick the file, and type your recovery key.
Your accounts appear. Compare a couple of codes with the old computer or your phone.
Open Shield on the new computer and check that a new backup was written there.

You can keep Never Lose Codes on both computers. Note that they don't sync: an account added on one won't appear on the other until you restore a newer backup. Restoring only adds missing accounts, so doing it again later is safe.

If the old computer is gone

Look for a copy of a backup file anywhere you might have one: a USB stick, external drive, cloud folder or email. Then follow steps 4 to 7 above. If you have no backup file at all, the codes can't be rebuilt from the recovery key alone. The key opens backups; it doesn't contain your accounts. Use your phone's copy if you have one, or follow Lost your authenticator codes? What to do now.

Same computer, after clearing Chrome

If you cleared Chrome's browsing data or reset Chrome on the same computer, your encrypted codes may still be there, but Chrome's stored key is gone. Never Lose Codes will ask for your recovery key. Type it and your codes open. If the extension itself was removed, reinstall it and restore from the backup files that are still in your Downloads folder.

A new Chrome profile on the same computer

Each Chrome profile keeps its own extensions and data. If you start using a new profile, Never Lose Codes in the new profile starts empty. Install it there, choose I have a backup file, and restore your newest backup with your recovery key, the same as on a new computer. The backup files are shared through your Downloads folder, so they're already there.

Before you wipe or hand over the old computer

Your accounts appear on the new computer and their codes work on at least one site.
The Shield page on the new computer shows a green check for the backup file.
You have your recovery key saved somewhere that isn't the old computer.
You've copied at least one backup file off the old computer.
Your sites' own recovery codes are saved somewhere safe, too.

Once those are all true, remove Never Lose Codes from the old computer and delete its Downloads/NeverLoseCodes folder if someone else will use the machine. The files are encrypted, but there's no reason to leave them behind.

A habit worth keeping

Once a month, copy the newest backup file somewhere off the computer. It takes a minute and turns "the computer died" from a lockout into a 5-minute restore.

Never Lose Codes is a Chrome extension that keeps your 2FA codes encrypted on your computer, with backup files you hold and a recovery key. See how it works.