The Cost of Dust

Dust is a balance whose value is less than the cost of moving it. It is economically stranded, and every active wallet accumulates some.

How it accumulates

Change from transactions on networks using an unspent-output model.

Residual balances left after a swap or a withdrawal.

Airdropped tokens of negligible value, frequently unsolicited.

Rounding in protocol interactions.

Why it matters more than the amount suggests

On unspent-output chains, it costs you later. A wallet holding many small outputs pays more to spend, because transaction size scales with the number of inputs. Dust makes future transactions more expensive even if you never move the dust itself.

It complicates records. Every balance is a line in tax accounting, regardless of size.

Dust attacks. Small amounts deliberately sent to addresses to link them through subsequent spending. The amount is trivial; the deanonymisation is the point.

What to do about it

On account-based chains, dust in a token is simply a small balance. It costs nothing to leave and cannot be moved economically. Hide it in the wallet interface and ignore it.

On unspent-output chains, consolidate during quiet periods. Combining many small outputs into one costs a fee proportional to the number of inputs, and doing it when fees are low is considerably cheaper than being forced to spend those inputs during congestion.

This is the closest thing to free money in fee management, and it requires only doing housekeeping at the right time.

For unsolicited tokens, do nothing at all. Interacting with them is the attack. Hide and ignore.

The consolidation timing

Weekend mornings, during a period when the network is quiet. The operation is never urgent, so there is no reason to do it at any other time.

Check the fee level before and after to confirm the saving. The difference between a consolidation at the weekly low and one at the weekly peak is commonly three to five times.

The dust attack defence

Do not spend dust you did not expect. Spending it together with your own outputs links the addresses.

Wallets with coin control let you select which outputs to spend, which is the direct defence. Where that is unavailable, leaving unexpected dust untouched achieves the same thing.

The preventive measure

Fewer, larger transactions produce less dust than many small ones.

Withdrawing quarterly rather than monthly, and consolidating deliberately rather than accumulating, keeps the output count low and future transactions cheap.

Venues that let you specify the withdrawal amount precisely, and that publish their minimums, such as platforms that do not round the fee up, make it easier to avoid creating residual balances in the first place.