Is it safe to sync passwords that have been deleted on another device?

Question

A little while ago, I deleted my passwords in Google Chrome, thinking that this would only apply to that particular device. Unfortunately, I found that this action had been synced to all devices, meaning that I lost the passwords.

I have recently found that Google Chrome on one of my devices is unsynced (more specifically, it is inviting me to Sign in to start sync). On this device, my old passwords are all there.

I would like to be able to sign in here and get the passwords synced across to my other devices. However, I'm terrified that the opposite will happen, and the passwords will be deleted from the device that still has them.

What will happen if I sync from the device I've found? Will I get the passwords on all devices? Or will I lose them altogether?

Alternatively, is there a 'safe' way to transfer the passwords that guarantees I will not lose them? If it helps, I can get up both synced and unsynced browsers on the same system (Chromium and Google Chrome).

Answer 1

To answer my own question: I decided to back up the file containing the passwords and try it out. My worst fears were realized, and the passwords were indeed deleted from the unsynced device.

I can get back into my starting position by copying the file I'd backed up back into its original location and restarting Chrome. This time, because sync was turned on, the passwords did indeed end up syncing across to my Google account and eventually to my other devices.

So the slightly convoluted instructions for anyone else who might get into this situation are:

1. Locate the file where Google Chrome stores passwords (normally C:\Users\$username\AppData\Local\Google\Chrome\User Data\Default\Login Data on Windows, ~/.config/google-chrome/Default/Login Data for Google Chrome or ~/.config/chromium/Default/Login Data for Chromium on Linux or /Library/Application Support/Google/Chrome/(Default|{PROFILE})/Login Data on Mac and copy the file to a safe location.
2. Turn on sync in the unsynced browser. Wait for sync to happen - both the synced and the unsynced devices should show the same set of passwords. If the lost passwords show up in both browsers, then great. Otherwise...
3. Close the browser you have just synced up, copy the backed up Login Data back into its original location and relaunch Chrome. Wait for sync and you should get the lost passwords back into your account.