Private Key Sweep vs. Import – A Beginner’s Guide

By: Ofir Beigel | Last updated: 1/22/23

Knowing the difference between importing and sweeping a private key is important, especially if you use paper wallets. In this post, I’ll explain the difference between the two methods and what to look out for.

Sweep vs. Import Summary

Sweep and Import are ways of transferring a private key onto a software wallet.

Import keeps the Bitcoins on the original private key, while Sweep sends the Bitcoins to a whole new private key connected to the software wallet. As a rule of thumb, sweeping is more recommended than importing.

That’s sweep vs. import in a nutshell. For a more detailed guide keep on reading, here’s what I’ll cover:

1. Importing a Private Key
2. Sweeping a Private Key
3. Sweep and Import Support
4. Conclusion

1. Importing a Private key

When you import a private key, you’re simply adding it to the collection of private keys in your software wallet.

If any bitcoins belong to the private key, they’ll now be included in your software wallet’s balance and remain assigned to that private key.

For instance, if you are importing a private key from a paper wallet, its bitcoins are now accessible via both the paper wallet and the software wallet. If anyone else gets their hands on that paper wallet, or have already had access to its private key, they can still spend its bitcoins.

Additionally, any bitcoins sent to the paper wallet in the future will be credited to both the paper wallet and the software wallet.

Another important thing to keep in mind is that once any of the private key’s bitcoins are spent using the software wallet, the private key will be completely depleted of its bitcoins – Even if only a portion of its bitcoins are spent!

This is because Bitcoin transactions spend the entire balance of a private key, and send any leftover change to a newly generated private key in the software wallet.

For other issues that can occur when importing a private key, read this post.

When Should You Import a Private Key?

You should only do an import if you generated the private key (or paper wallet) yourself and no one else has ever, or will ever, have access to it. If someone else gave you the paper wallet, or its private key has been seen, you should sweep it instead.

2. Sweeping a Private Key

Sweeping a private key is the same as importing it, but with an extra step – all of the bitcoins belonging to the private key are sent to a new Bitcoin address on your software client.

This is done via a Bitcoin transaction, so an internet connection is required to send out the transaction and complete the sweep.

After the sweep is complete, the original private key will be completely depleted of funds and all of its bitcoins will belong to a new private key in the software wallet.

Since sweeping involves sending a transaction (to yourself), a miner fee will be deducted from your balance.

When Should You Sweep a Private Key?

You should sweep a private key if someone else had access to the private key (e.g. if someone gave you a paper wallet or the private key was published online).

This will prevent a potential hacker from ever being able to spend the bitcoins associated with it.

As a rule of thumb, if you’re in doubt of whether to import or sweep a private key, you should probably sweep it. Sweeping solves many of the issues that can arise from doing an import.

3. Import and Sweep Support

Here’s a short list of Bitcoin wallets that have the built-in capability to import and/or sweep a private key:

• Ledger
• Trezor
• Electrum
• Coinomi
• Edge
• Exodus
• Bitcoin Core
• Jaxx
• Mycelium

4. Conclusion

Both Sweep and Import are valid methods for transferring a private key into a software wallet. Sweep seems to be the safer way to go, although you will need an internet connection and it will cost you a miner fee. A small price to pay for some peace of mind.

Have you imported or swept a paper wallet in the past? I’d love to hear about it in the comment section below.