What is finality?

Landing in a block is not the same as being final. On many chains a reorg can still swap out a fresh block, and your transaction goes with it. Finality comes in two flavors: certain under the protocol's rules, or so probable that nobody bets against it.

Chains get there differently. Bitcoin's finality is probabilistic: every new block makes a reversal less likely, and six confirmations, about an hour, is the usual bar. Ethereum finalizes after two epochs of 32 slots each, about 12.8 minutes. Solana confirms a block optimistically within about a second and finalizes it in roughly 13 seconds. Alpenglow, a new Solana consensus, targets around 150 milliseconds. It is not live on mainnet yet, and how close it gets to that target there is still an open question.

L2s add a step. The Arbitrum sequencer confirms a transaction almost at once. Settlement on Ethereum waits for the batch to be posted and, for withdrawals, for a challenge window of about seven days. Exchanges and bridges each pick how many confirmations to wait for, which is why deposit times differ so much between venues.

Take an exchange that credits your ETH deposit only after Ethereum finalizes the block, about 13 minutes later. A SOL deposit to the same exchange shows up in under a minute.

Also called: transaction finality, settlement finality.

Cashboard does not track individual transactions or confirmations. The Chain status widget shows block height and block age per network and flags a chain as Lagging or Stalled when blocks stop arriving on schedule. If a deposit looks stuck, check that first.

• Chain status

• Block time
• Block height
• Layer 2
• Cross-chain bridge