A fee for the act, not the amount
A bank charges a percentage or a flat fee and either way the fee is a function of money. A blockchain charges for space. A Bitcoin transaction is a few hundred bytes that every node must store forever, and miners price it per byte; an Ethereum transaction consumes gas in proportion to the computation it triggers, and the sender pays for the gas. In neither case does the value being moved enter the price. Sending one satoshi costs the same as sending one bitcoin in the same transaction shape.
That is the whole origin of dust. Because the fee is fixed by the act and the balance can be arbitrarily small, there is always a balance below which moving it is pointless: the fee would consume it. On a busy day for the network the threshold rises with the fee, and a balance that was worth moving on Sunday may not be on Monday. The fee article covers why the fee moves; this one is about what it leaves behind.
Where dust comes from
- Remainders. Withdraw most of a balance and the fee, deducted from what is left, produces a fraction that was never worth anything on its own.
- Rounding. Exchanges and sites display balances to a few decimals and hold them to more; the part below the display is real and is dust by definition.
- Partial fills and conversions. Trade one coin for another and the odd lot at the end of the order is dust in the coin you sold.
- Strangers. An unsolicited transfer of a few cents’ worth is not generosity. It is either an advertisement, an attempt to link your addresses, or the first step of address poisoning: a look-alike address planting itself in your history. Leave it alone.
Bitcoin has a formal version of the threshold. Nodes running the reference software will not relay a transaction that creates an output worth less than a dust limit, a few hundred satoshis for a standard output, because such an output costs more to spend than it holds and would otherwise clutter the ledger forever. The limit is a network policy rather than a rule of the protocol, but in practice it means that below a certain size a Bitcoin payment cannot be made at all.
The minimum on this site
The withdraw window carries the same logic in one field. Each coin the site supports has a minimum withdrawal and a fee, both stored in the coin’s smallest unit and both shown to you, converted to ordinary units, in the warning text under the form. A withdrawal below the minimum is refused in the browser with a message that names the minimum and the coin, and it never reaches the wallet service.
The minimum is not a limit on what is yours. Everything below it is still your balance, can still be bet, and can be withdrawn the moment it is joined by enough to clear the line. It is a refusal to perform a transaction that would spend your money on the network and hand you nothing, which is what a withdrawal smaller than its own fee is.
What to do with dust
- Play it or top it up. A balance below the minimum can be staked here like any other; it is only the network it cannot reach. Adding to it until it clears the minimum is the other route out.
- Withdraw in fewer, larger transfers. Each transfer pays the act fee once. Splitting a balance into small withdrawals manufactures dust at both ends.
- Check the fee before the amount. If the fee is a visible fraction of what you are sending, the transfer is expensive; if it exceeds it, the site will refuse and you should not want otherwise.
- Never interact with dust you did not send yourself. Do not sweep it, do not reply to it, and do not copy any address from the row it appears in.
What is dust in crypto?
A balance too small to be worth moving, because the network fee to send it would equal or exceed it. It arises from remainders, rounding, partial fills and occasionally unsolicited transfers.
Why does the network fee not scale with the amount?
Because a blockchain charges for the transaction’s size or computation, not its value. Sending one satoshi costs the same as sending one bitcoin in the same transaction shape.
Why is there a minimum withdrawal on this site?
Each coin has a minimum and a fee stored in its smallest unit and shown in the withdraw window. A withdrawal below the minimum would spend the network fee and deliver nothing, so the window refuses it before sending.
Is a balance below the minimum lost?
No. It remains yours, can be staked, and can be withdrawn once the balance exceeds the minimum.
Someone sent me a tiny amount I did not ask for. What is it?
Most often an address-poisoning attempt or an attempt to link your addresses. Do not interact with it and never copy an address from that transaction.
- Bitcoin Core — dust output policy (the relay threshold for uneconomic outputs)
- Betkyo client source: store/CoinStore.ts (fee, minWithdraw, minDeposit, the View getters), component/common/popup/wallet/withdraw.tsx (minimum check and warning text)
