What is Gas Limit?

The gas limit is the ceiling you set on how much computational work a transaction may consume. If the operation needs less, you pay only for what is used; if it would need more than the limit, the transaction fails without completing. Wallets usually estimate a sensible limit automatically for you.

This matters because it is a safety cap. A correctly set gas limit ensures a simple transfer cannot suddenly cost far more than expected, while a limit set too low can cause a transaction to fail partway.

Example: a basic token transfer has a modest gas limit, but interacting with a complex DeFi contract needs a higher one; if you set the limit below what the contract requires, the transaction reverts.

Safety note: a failed transaction due to a too-low gas limit can still burn the gas it used up to the failure point, so do not set limits arbitrarily low to save money. Trust your wallet’s estimate for standard actions, and be cautious of any dapp asking you to manually raise the limit to unusual levels. Related terms include gas, gas fee, gwei, and smart contract.