When you link the extension to the desktop app and both already have entries, the extension shows You have two vaults.
Combine into one
The browser’s entries and files move into the desktop app’s vault. Exact duplicates are skipped, and entries that look almost the same are held back so you can decide. Afterwards, the browser unlocks with the desktop app’s master password.
Pick this when both vaults hold your own passwords and you want one list everywhere.
If the browser’s vault also syncs with other devices, combining moves only this browser. Those devices keep the old vault.
Keep them separate
The desktop app’s vault is added next to the browser’s. To switch, lock Bramble and choose Choose a different vault.
Pick this when the vaults are for different things, like work and personal.
After you combine
The old vault leaves the vault list. Bramble doesn’t delete it: it stays on this browser, out of sight.
Entries that look like ones the desktop app’s vault already has aren’t copied, and Bramble lists them. To bring them over, choose Copy them anyway.
If something didn’t copy, like a file or an entry Bramble couldn’t open, the old vault stays in the list so nothing is lost.