Gas Refund
A partial return of gas cost for specific actions that reduce a network's storage burden, such as clearing previously-used contract storage.
A gas refund is a partial return of gas cost (see Kaavon's "Gas Fee" glossary definition) for specific actions that reduce a network's overall storage burden — most commonly, clearing data from a smart contract's storage that's no longer needed, which a network wants to incentivize since smart contract storage is a genuinely scarce, costly resource for every node to maintain.
Gas refund mechanisms have been adjusted over time on major networks, generally to prevent them from being exploited in ways that didn't match their original intent — a documented example of how even a network's fee-incentive design can require real, ongoing refinement once deployed.
Examples
- A smart contract clearing data it no longer needs from storage can earn a gas refund, since this reduces the ongoing storage burden every node has to maintain.
- Gas refund mechanisms have been adjusted over time on major networks specifically to prevent exploitation that didn't match the original design intent.