Introducing NextBlock fee estimator

We are pleased to launch nextblock.is - our brand new fee estimator that is designed to make fee estimations that won't let your transactions get stuck in the mempool but also won't make you overpay.

How does it work?

The NextBlock estimator fetches a block template from Bitcoin Core and assesses all the transactions in given template. Then it computes at what miner fee rate a transaction needs to be broadcasted right now for it to be added into the next block.

• High = 99% probability your transaction will confirm in the next block
• Medium = 50% probability your transaction will confirm in the next block
• Low = 10% probability your transaction will confirm in the next block

A more detailed technical explanation can be found in the $1 Fee Estimator Readme by LaurentMT.

Why is this fee estimator different to others available?

There are many methods which attempt to provide you with a miner fee rate estimation, some of these are integrated into bitcoin wallets, some are standalone applications. To date we have found most to be unreliable particularly during moments of miner fee rate volatility. Any application or tool which tells you "your transaction is expected to be confirmed within 4/6/12/24 blocks" is being dishonest as its calculation uses already confirmed blocks to draw this conclusion which is a flawed methodology.

By assessing the unconfirmed transactions within the mempool, this tool provides instead an instant snapshot probability for being confirmed in the next block. Attempting to calculate beyond this (i.e. for your transaction to be confirmed 6 blocks from now) introduces too many variables which would make any calculation mathematically unsound.

What's next?

While we wanted to make this tool to be publicly available by everyone, Samourai users are going to have even easier access because NextBlock estimations are already available in Samourai Dojo (v23 and beyond) and these fee estimations will be built into Samourai Wallet in the upcoming release.

Next Block

Bitcoin transaction fee estimator to get you to the next block.

Thank you

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