Both Arbitrum and zkSync aim to reduce transaction costs on the Ethereum network, but they do so using different methods. Arbitrum’s Optimistic Rollup aggregates multiple transactions into a single batch, reducing the data that needs to be posted on-chain and thus lowering gas fees. Users typically experience significantly reduced transaction costs compared to the Ethereum mainnet. zkSync’s zk-Rollup also batches transactions but relies on zero-knowledge proofs to validate these batches on-chain, which minimizes gas consumption even further. zkSync’s method often results in even lower fees compared to Arbitrum, especially for high-volume transaction scenarios. However, the complexity of generating zk-SNARKs can introduce additional computational costs, which may offset some of the gas savings in specific cases. Overall, both platforms offer substantial cost reductions, with zkSync generally providing the lowest fees due to its efficient proof system, making it particularly attractive for microtransactions and high-frequency trading applications.