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First aid · Backups
How to back up the file before touching anything
Before trying a single password, before reinstalling anything and before asking for help: copy. It is the most boring advice on this whole site and the one that has saved the most wallets.
What to copy, depending on your wallet
| Your wallet | What to copy |
|---|---|
| Browser extension | The entire browser profile folder |
| Bitcoin Core | The wallet.dat file, better still the whole folder |
| Electrum | The wallets folder, complete |
| Desktop app | The app’s data folder, complete |
| Keystore or loose key | The file exactly as it is, without renaming |
| Mobile app | A phone backup, if your system allows one |
Notice that almost every row says «the whole folder». That is deliberate: going hunting for the specific file inside a data folder is the fastest way to leave out exactly the one that mattered. Copy too much, not too little.
How to do it properly
- Close the wallet app before copying. Copying a file while the program has it open can produce an incomplete copy.
- Copy, don’t move. The original stays where it is, untouched.
- Make at least two copies in different physical places: a USB stick and an external drive, for example. A single copy on the same computer is not a backup.
- Check the copy is the same size as the original. A 0-byte file is a failed copy, and it happens more than you would think.
- Label the copy with the date and where it came from. In six months you won’t remember.
Where NOT to store the copy
Don’t upload it to the cloud or email it if the wallet has no password: in that case the file is money in plain text. If the wallet is encrypted the risk is lower, but it is still better kept on your own physical media. And never, under any circumstances, upload it to a site offering to «analyse» it.
A detail that saves cases
If you find several versions of the same wallet from different periods, keep them all. Don’t keep only the most recent. An old copy may carry a simpler password you had forgotten you used, and in pre-2013 wallets old and new copies contain different addresses. See the difference between the backup and the wallet itself.