# What is finality? When a transaction is truly done

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> License: CC BY 4.0 (attribution + link) · © 2026 BlazePhoenix
> Updated: 2026-08-05



Finality is the guarantee that a transaction is permanent and cannot be undone. Right after inclusion a transaction is probabilistically final: it is done, but a chain reorganisation could in principle replace that block. With each additional block on top, the chance of reversal falls toward zero, which is why exchanges wait for several confirmations on large deposits.

## Layer 2 and settlement

Layer 2 networks like Base, Optimism and Arbitrum give fast local confirmation and then settle to Ethereum, where the strongest finality lives. For everyday swaps the local confirmation is enough; for large or bridging moves it is worth understanding that full settlement to the base layer takes longer. Either way, the explorer shows you exactly where your transaction stands.

**Verify it yourself:** Watch a fresh transaction gain confirmations on an explorer: the block depth counter is the plain-English version of how final it is

Related: https://blazephoenix.xyz/learn/what-is-a-transaction · https://blazephoenix.xyz/learn/what-is-layer-2 · https://blazephoenix.xyz/learn/ethereum-for-traders