Crypto glossary
Finality
Finality is the point at which a blockchain transaction can no longer be reversed or altered, either with practical certainty or by protocol guarantee.
Finality describes how certain it is that a confirmed transaction will stay in the chain. On proof-of-work chains such as Bitcoin it is probabilistic: each new block added on top makes a reversal less likely, so recipients wait for several confirmations. Many proof-of-stake and BFT-style chains offer deterministic finality, where a block is final under the protocol's rules once validators have signed off on it.
Ethereum finalises blocks in checkpoints, usually about 13 minutes after a block is proposed, and reverting a finalised block would require at least a third of all staked ETH to be slashed. Exchanges and bridges set their deposit rules around finality, and rollups depend on it twice: on their own chain and on Ethereum.
Faster finality improves the user experience but often requires a smaller or more coordinated validator set. A network that stops finalising, as Ethereum briefly did in May 2023, keeps producing blocks but cannot offer the same guarantees until finality resumes.
Example
An exchange may credit a bitcoin deposit after three to six confirmations, roughly 30 to 60 minutes, while an Ethereum deposit may be credited once its block is finalised.
Related terms
Latest articles on Finality
- Sei Proposes Autobahn Consensus Upgrade Delivering 250ms Transaction Finality Speed
- Ethereum Researchers Propose Reducing Transaction Finality Time to Four Minutes
- Solana’s Alpenglow Upgrade to Cut Network Finality to 150 Milliseconds Goes Live Today
- Solana Sets October 21 for Alpenglow Upgrade Targeting 150ms Finality
- Solana’s Faster Upgrade Moves to Testnet, Cutting Finality to 0.15 Seconds
