Use exported wallet.dat from unsynced client in synced client

Question

I've created a receiving wallet with bitcoin core (on windows). The client, however, is not synced to the network. I have already received a small amount, which I can see by using any blockchain explorer.

I would assume it's possible to create a backup of the encrypted wallet, copy it to my macbook, and use it in a core client (which is synced)?

If that works, then I'm still not sure how the synced client would know anything about the wallet's balance without running over all blocks again until it finds its transactions. I would think that this rescan goes from latest to oldest block, in which case it should definitely be a lot quicker then syncing the unsynced client.

Am I on the right track here or do I have it all mixed up and still haven't understood it? Thank you very much.

Answer 1

I would assume its possible to create a backup of the encrypted wallet, copy it to my macbook and use it in a core client (which is synced)?

Yes, you could certainly do that. Just be careful not to overwrite the wallet on your macbook if it also contains bitcoin.

I'm still not sure how the synced client would know anything about the wallets balance without running over all blocks again until it finds its transaction.

That is exactly what needs to be done. You can do that using a command called rescanblockchain after you open the new wallet on a synced node.

I would think that this rescan goes from latest to oldest block, in which case it should definitely be a lot quicker then syncing the unsynced client.

This is incorrect. Rescans still go from the oldest to the newest. However, it would still be faster, because you aren't downloading the blocks fresh (they're already stored on your macbook) and you aren't verifying all the transactions again, you're just looking for ones which are related to your wallet.