How a crypto transaction gets confirmed

What happens after you press send: broadcast, the mempool, blocks, confirmations and finality, plus what “pending” and “dropped” really mean.

Updated 15 Sept 2026 · Beginner · 3 min read

In short

After you sign and send, your wallet broadcasts the transaction to the network, where nodes hold it in the mempool until a block includes it.
A transaction is pending while it is waiting. It gains confirmations as more blocks are added, and stronger finality as reversal becomes less likely or impossible.
A transaction can also be replaced, cancelled or dropped if its fee is too low or it becomes invalid, which is why wallets and exchanges sometimes show different statuses for a while.

From your wallet to the network

When you press send, your wallet builds a transaction, signs it with your private key and broadcasts it to one or more nodes. Those nodes check basic rules before relaying it onwards: the signature must be valid, the format must be correct and the funds being spent must still be available.

If the checks pass, the transaction spreads across the network within seconds. At that point it exists, but it is not confirmed yet. Your wallet usually labels this stage pending.

What the mempool does

A node keeps valid unconfirmed transactions in its mempool, short for memory pool. This is the waiting room for the next block. On Bitcoin, miners usually choose the transactions paying the highest fee rate first. On Ethereum and its layer 2s, block builders and sequencers also prefer the transactions that pay enough to make inclusion worthwhile.

This is why fee level matters. A generous fee can be confirmed in the next block or two; a low one may wait for quieter conditions. You can watch that pressure on the Bitcoin fees page or the gas tracker.

What a confirmation means

The first confirmation happens when a block includes your transaction. The ledger now shows it as part of the latest accepted chain. Each later block built on top of that one adds another confirmation, making it harder to undo.

Different chains reach confidence in different ways. On Bitcoin, confirmation is probabilistic: one block can, in principle, be replaced by a competing block, but the chance falls quickly as more blocks bury it. On Ethereum, a block can be proposed every 12 seconds, and the network finalises blocks after two epochs, about 13 minutes. Wallets call a transaction “confirmed” as soon as a block includes it, before that finality.

Why exchanges wait for several confirmations

Exchanges and merchants care about settlement risk, not only about whether a wallet shows a tick. A small Bitcoin payment might be accepted after one confirmation for convenience, but an exchange crediting a large deposit may wait for three, six or more because reversing a deposit after it has let you trade or withdraw is expensive.

The wait depends on the chain, the asset and the exchange's own policy. Tokens issued on a chain inherit that chain's confirmation behaviour, so an ERC-20 deposit follows Ethereum's rules, while a stablecoin on Solana follows Solana's.

Pending, replaced, cancelled and dropped

A transaction stays pending until a block includes it or until the network stops considering it valid. On EVM chains, a wallet can replace a pending transaction by sending another with the same nonce and a higher fee. That is what “speed up” does. Sending a zero-value transfer to yourself with the same nonce is a common way to cancel one before it confirms.

A transaction is often called dropped when nodes evict it from their mempools, usually because the fee was too low, the mempool became crowded or another transaction made it impossible to confirm. Wallets and explorers may disagree for a while because each node has its own mempool, but once a block includes a replacement, the original is no longer going through.

How to check what is happening

Look up the hash in our transaction lookup for EVM transactions, or the Bitcoin transaction accelerator for a Bitcoin transaction’s status and fee rate.
Check whether the fee is low compared with current network demand.
If the transaction is still pending and your wallet offers speed up or cancel, make sure you understand which action you are taking before you sign again.
If an exchange deposit is confirmed on the chain but not credited, compare the confirmation count with the exchange's stated requirement before contacting support.

Put it into practice

Transaction lookup →Bitcoin fees page →Gas tracker →