I disconnected my Ledger/Trezor but still can open Yoroi on my computer and view balance and transaction history.
It is possible to open up the Yoroi extension and see your balance at any time, even without connecting the Ledger device, because your ADA are stored on the Cardano blockchain. However, your hardware wallet is needed in order to send ADA.
Updated on: 14/08/2025
Thank you!