Replace-by-Fee (RBF) on Bitcoin lets you replace a transaction with a new one (with a higher fee) to bump it up in the queue to get confirmed quicker by the network.
While it can be useful to get your BTC transaction unstuck from the mempool, it allows for some not-so-nice people to snipe Bitcoin assets (think Ordinals or Runes) that you’re trying to buy by cutting in line.
In this guide, we're diving into Bitcoin’s replace-by-fee (RBF), how it works and how you can protect yourself from mempool sniping when you’re buying and selling Ordinals and Runes on Magic Eden.
When you send BTC or any other asset on Bitcoin, you have to pay a fee to the miners as the whole network relies on their work.
The higher the fee, the happier the miner—and that means your transaction gets picked up faster. This keeps them motivated, even when the network is super busy and clogged with transactions vying for their attention.
That’s when you might start thinking about raising your fee to make the miners grab your transaction over someone else’s, and this is where Replace-by-Fee (RBF) comes in.
If your transaction isn’t confirmed yet, you can increase its fee, giving it a better chance of being chosen.
If your fee is too low, you could end up waiting hours for confirmation. But if you set it too high right away, you’re probably just overpaying. That's why RBF is used - it lets you begin with a lower fee, and if that doesn’t work, you can bump it up to make the miners more happy.
RBF lets you replace your original transaction with a new one that has a higher fee. Then, the new transaction gets confirmed, and the old one gets kicked out of the mempool, so it doesn’t get mistakenly confirmed.
The mempool is basically a “waiting room” for transactions before they’re added to a block on the blockchain. This wait can last from a few minutes to hours, especially when the network is busy.
RBF is great if you need to confirm your transaction faster, but it does come with a risk—fee sniping. That’s when someone comes in with the same transaction details as you but pays a higher fee. This increases their chances of getting their transaction confirmed before you.
This can be annoying if you’re trying to buy an Ordinal or Rune and someone jumps in with a higher fee, grabbing the asset you were after.
Your funds are refunded since the old transaction was dropped, however, you still miss out on the assets you were trying to get.
But there is a solution: Mempool Protection.
Users fear not – Magic Eden offers protection from RBF sniping with Mempool Protection, and it’s up to you whether you want to use it.
Mempool Protection is available for both Ordinals and Runes purchases on Magic Eden.
Mempool Protection on Magic Eden is like your personal bouncer for transactions. It lets you set a cap on the fee you’re willing to pay to keep transaction snipers at bay. If someone tries to RBF your transaction with a higher fee, your fee automatically bumps up to stay ahead of theirs, making sure miners still pick your transaction over theirs.
Magic Eden’s Mempool Protection feature is easy to use. Just tick the box when you’re making a purchase, and you’ll get a chance to bump up your fee. You can pick any multiplier you want—just make sure you have that amount and you’re ok with paying it.
Your funds stay put until the transaction is confirmed. So, even if you set a sky-high fee, if someone else wants to pay more, your transaction will fall through and the funds won’t be spent.
If no one tries to RBF your transaction, you’ll pay the network’s minimum fee. If someone does, you’ll pay more (up to your limit), but never more than your max.
You can choose from two types of Mempool Protection - Pre-purchase and Post-purchase protection. Magic Eden's Mempool Protection works on all Bitcoin assets, including Rare Sats!
When you’re buying an Ordinal or Rune on Magic Eden, you can tick the Mempool Protection box before you finalize your purchase. This feature lets you set a maximum fee you’re willing to pay.
If someone tries to snipe your purchase with a higher fee, Mempool Protection will automatically bump up your fee to be higher than theirs (up to your limit), so your transaction gets picked and theirs gets dropped.
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Of course, there’s still a small chance that a sniper might offer more than your maximum fee if they’re willing to pay more than you.
But overall, Mempool Protection gives you a better opportunity of fending off RBF snipers.
If you forgot to add pre-purchase protection to your transaction or realize later that you want protection against sniping, Magic Eden has your back with post-purchase protection.
Post-purchase protection works just like the usual Replace-by-Fee feature.
Check your Pending Orders tab, and if your transaction is still hanging around waiting to be confirmed, you’ll see a “Top Fee” message in the Status field. If it’s being replaced, you’ll see “Getting Replaced,” and you’ll have the chance to up your fee. Magic Eden will show you what the sniper is paying, so you can outrun them with a higher fee.
You can only replace unconfirmed transactions in Bitcoin, and RBF is one way to do it. Using RBF, you send out the same transaction again but with a higher fee. If the higher fee gets confirmed, the old transaction is dropped from the mempool.
There’s also Child Pays for Parent (CPFP), which works a little differently. Instead of replacing the transaction, it adds a higher fee to the “parent” transaction that’s stuck in the mempool. This fee boost helps get both the parent and your new transaction confirmed faster by miners. These protections can help you guard against snipers, whether you are etching runes or buying Ordinals.
Replace-by-Fee (RBF) is useful when your BTC transaction is stuck in the mempool. However, it can be pretty frustrating when your transaction gets bumped for someone else’s when you’re trading on-chain assets.
At Magic Eden, we’re combating that issue with Mempool Protection. It lets you set the maximum fee you’re willing to pay, so your transaction doesn’t get replaced just because someone else throws in a few extra chunks of change.
Connect your wallet to Magic Eden to snap up the latest Ordinals or your favorite Runes tokens.
The information provided on this website is provided for general educational purposes only and is in no way financial or investment advice. Certain information may have also been provided to us or prepared by third parties; these materials are provided for convenience and are not an endorsement by Magic Eden. Magic Eden is not liable for any errors, changes or amendments to such information, including any actions taken in reliance on such information.
