What it is
On Ethereum, every operation, from sending Ether to executing a complex smart contract, requires a certain amount of "gas." The gas limit acts as a cap set by the transaction sender, indicating the maximum gas units they are prepared to pay for the transaction to complete. If the transaction uses less gas than the limit, the unused portion is refunded; if it exceeds the limit, the transaction fails.
Gas limits are crucial for managing transaction costs and preventing infinite loops in smart contracts. Users often set a gas limit slightly higher than the estimated requirement to ensure their transaction goes through, especially during network congestion. Miners and validators prioritize transactions with higher gas prices, so an insufficient gas limit can lead to transactions being stuck or failing, impacting user experience and application functionality.
Why it matters
Retail investors need to understand gas limits to avoid failed transactions or overpaying for network fees, especially when interacting with DeFi or NFTs.
Reviewed under editorial standardsUpdated September 26, 2026Not investment advice