### ZK-Rollups

## Finality

This table presents the key metrics on the average efficiency and cost for validity proofs of zero-knowledge rollups that submit state updates to the Ethereum network over the past 90 days.

Date Range: The start date for each of the four selectable dates is defined as the day preceding the current calendar date. This approach ensures the inclusion of the most recent complete data set for analysis.

Transactions (txs) per Proof: This metric covers the average count of L2 transactions in a single proof submitted for verification on the L1 network.

Proving / Finality Time: The average duration from the instantiation of a submitted proof to its verification on the L1 network. For zkSync Era, the state update time can be found in the info box on the timestamp.

Proving / Finality Time (Per 100 txs): This metric follows the methodology of finality time calculation, with an adjustment for L2 transaction size. It is calculated by dividing the average finality time by the average number of L2 transactions per proof and scaled by a factor of 100. This normalization process facilitates a standardized comparison of proving and finality times.

On-Chain Finality Cost: This cost refers to the expenses incurred to generate proofs and update the rollup's state on the L1 network.

On-Chain Finality Cost (Per Tx): This metric presents the average cost incurred on the rollup to achieve finality for an L2 transaction. It is determined by dividing the on-chain cost associated with finalizing the batch by the number of L2 transactions recorded within that batch.