Quick ways to check balances on old wallet files

Hey everyone, So I’ve got a ton of old wallet files stored on my computer. I’m pretty sure most are either empty or just have a little Bitcoin dust in them. What’s the simplest and quickest method to check their balances? And can anyone tell me if there’s a way to find out if that dust has made any cash from forks like Bitcoin Cash?

I'm going to ignore the "fastest" and answer the "easiest" question: install Bitcoin Core, load all wallets, then let it sync. Depending on your hardware this may take a day (or longer). Once done, check the balances. There's a website for this, but it's not always reliable. The fastest way is to export your addresses and check them on a block explorer if you have only a few addresses. Or import them into a Forked wallet, but know that you shouldn't trust them. So use a VM or spare laptop to protect your system from malware. Good point. Somehow I totally assumed it's Bitcoin Core.

Why not tell us first what wallet software did you use to generate these "bunch of old wallet files"? And tell us about the year when was these wallets created? If those wallets were created before August 2017, some of your wallets with BTC balances during the hard fork should contain Bitcoin cash. My suggestion instead of loading all wallet files into your bitcoin core or any wallet software. I recommend do it on an offline PC for safety purposes and then copy all addresses and transfer them to an online PC then check them using this tool below. - https://bitcoindata.science/bitcoin-balance-check

If you don't know how to use Bitcoin Core, then the easiest answer is to export the keys and import them into Electrum. If you can't export them, for whatever reason, then just let it sync, as told by LoyceV. Trying to figure out a faster solution will take longer than just letting it sync.

Thanks for mentioning my tool. I made it because I always needed something like that to control my addresses balance of different wallets. Anyway  all data came from mempool.space,  a block explorer. Any block explorer can do the job! No need to download any app

Because OP did not know whether those wallet files have bitcoins, it's not possible that OP knows what addresses have bitcoins. This means he need to use the command dumpwallet with command line.

If you want to check whether the address contain forked coin, you can use multi-chain block explorer (such as https://blockchair.com/) although you must an address at a time. https://findmycoins.ninja/ created specifically to find amount forked coin, but it will only show result when the address have 20 TX or less.

As far as I know, you'll also need to convert several of the addresses to it's new Fork-format before you can find them. That site is tricky, because it's incomplete. Send to pubkey transactions aren't shown (which means you could overlook very valuable Forkcoins), and there might be more limitations that I don't know of. This site can be helpful, but don't rely on it.

It depends on each forked coin. For example, BCH let you use both legacy (starts with 1... or 3...) and CashAddr format (starts with q... or p...) interchangeable. The community/developer even offer converter tool on https://cashaddr.bitcoincash.org/. That's right, but it remains easiest website to use.

I'm just very careful with it since I saw no Forks mentioned at all for an address that mined 50 Bitcoins in the early days, and showed up as empty on this site. One could argue that's correct, as the address didn't receive it but the pubkey did, but if you overlook it because of that, that's a $25k mistake.

If I just want to check the balance of some old wallet.dat files (most likely they are all empty, but you never know), would it be OK if I launch Bitcoin Core, restore the wallet and then check the balance of the addresses in the Receiving Addresses window? Would that window show all addresses of that wallet that might contain some BTC?

If you install and let your Bitcoin Core completes its synchronisation with Bitcoin blockchain, you will see your wallet balance after that. After sync, you can use two commands in console to check. Details on two command utility.