Rollups Pay Ethereum: The Hidden Fees Behind Layer 2 Transactions
Ethereum's Layer 1 and Layer 2 transaction fees are closely connected, but it may not be clear who is paying Ethereum when using rollups. According to Ethereum.org, optimistic rollup fees include the cost of executing a transaction on Layer 2 and publishing data to Ethereum.
Rollup operators collect these fees from users and use part of that revenue to cover their Ethereum expenses, which can range from data publication to settlement and other costs. This batching process is key to making Layer 2 transactions substantially cheaper than individual Layer 1 transactions.
ZK rollups also pay Ethereum for proof verification, consuming around 500,000 gas per verification on Mainnet. While this may seem counterintuitive given that computation happens mostly outside of Ethereum, it's an essential part of the process.