Dust

Definition

Dust refers to very small cryptocurrency amounts, with a specific transaction-policy meaning in Bitcoin. A Bitcoin output may be considered dust when its value is too low relative to the estimated cost of spending it under a node's configured dust-relay assumptions. The threshold depends on factors such as output type and policy settings; there is no single amount that describes every output under every configuration. Dust policy should not be confused with a universal consensus prohibition on small payments. Separately, a wallet can contain outputs that are technically spendable but uneconomical at prevailing fee rates. Unsolicited tiny payments can also be used in attempts to analyze wallet activity, although receiving dust alone does not reveal a private key. Combining such outputs with other funds may create public links, making coin selection and privacy considerations relevant before spending them.