Transaction accelerator

What to Do if Your Bitcoin Transaction Gets "Stuck"

The number of transactions on the Bitcoin network has steadily increased over the years. This means more blocks are filling up. And as not all transactions can be included in the blockchain straight away, backlogs form in miners’ “mempools” (a sort of “transaction queue.”)

Miners typically pick the transactions that pay the most fees and include these in their blocks first. Transactions that include lower fees are “outbid” on the so called “fee market,” and remain in miners’ mempools until a new block is found. If the transaction is outbid again, it has to wait until the next block.

This can lead to a suboptimal user experience. Transactions with too low a fee can take hours or even days to confirm, and sometimes never confirm at all.

Fee Bumping

The recommended approach to "accelerating" a transaction is to perform a fee bumping methods, either replace-by-fee (RBF), or child-pays-for-parent (CPFP), which are available to:

• Sender of the Bitcoin transaction: Replace-by-fee (RBF), and Child-pays-for-parent (CPFP)
• Recipient of the Bitcoin transaction: Child-pays-for-parent (CPFP)

Bitcoin transaction accelerators

Mining Pool Accelerators

A mining pool may offer a premium service in which they will prioritize a transaction, usually for a fee. The ability for that pool to get a transaction confirmed is limited to their ability to get a block confirmed -- and most pools have a tiny fraction of the hashrate. For example, if a pool has 10% of the hashrate, they mine about a block every 100 minutes (1 hour and 40 minutes), on average. If a pool has 5% of the hashrate, then they mine one block about every 200 minutes (3 hours and 20 minutes), on average.

• Binance Pool - is a prominent cryptocurrency mining pool operated by Binance, one of the world's leading blockchain and cryptocurrency exchange platforms. In addition to its mining services, Binance Pool offers exclusive transaction acceleration services for VIP users, ensuring swift confirmation of their cryptocurrency transactions.

• ViaBTC - Working as of December 30, 2020. ViaBTC implemented this service to protest against the prior 1MB limitation of the Bitcoin network. ViaBTC gives priority to user-submitted transactions for the next mined blocks by the ViaBTC pool. The only requirement is the transaction must include a minimum fee of 10 sat/B. The free-to-use nature of the service may have made it widely popular as every hour, the number of transaction requested reaches its limit (of 100) and it is common to be presented with the message “Submissions are beyond limit. Please try later.” on the top middle of the page. This means one must wait for the next hour to try a new submission. After submitting a transaction, there is a wait for the next block to be mined by ViaBTC Pool.

• BTC Nitro - Similar to the services listed above, BTC Nitro works with a number of mining pools and will insert your transaction into a block about to be be mined for a flat fee of $25 USD. They also guarantee a full refund of the fee if the transaction you want to accelerate doesn't get confirmed within 24 hours of payment.

• BitAccelerate - Working as of August 22, 2018. BitAccelerate offers both free and paid versions of its service. The free version serves as a rebroadcasting service. If the transaction does not have any unconfirmed inputs, a premium version is offered. The company collaborates with one of the largest mining pools, prioritizing transactions for their customers.

Third Party Accelerators

There are additional services claiming to be able to "accelerate" a transaction. Their ability to get a transaction confirmed faster is limited to re-broadcasting your transaction, to help in the situation where that mining pool has dropped your transaction already. The Bitcoin Core client already does re-broadcast a "stuck" transaction periodically to peer nodes, though these services possibly may broadcast a transaction directly to known mining pool nodes. These services could also pay a mining pool to include your transaction, just as you could do that yourself.

It is likely these "transaction accelerators" that are not working with mining pools are not actually helping to get a transaction confirmed faster.

• https://btcnitro.com/ This is the free service offered by BTC Nitro that just rebroadcasts your transaction to the blockchain using various public and private nodes.
• https://txbooster.com Free Bitcoin transaction accelerator. The service actually rebroadcasts your transaction via different nodes.
• https://btcaccelerators.com BTC Accelerator is a fast and high-performance bitcoin transaction accelerator tool that reduces confirmation times.