Small outputs, also called dust
A small output is a piece of bitcoin so small that the fee to spend it at an ordinary rate would be more than the piece is worth. People call it dust. It still belongs to the address. It is just not worth moving on its own.
What the note says
- Good
No output costs more to spend than it holds at typical fees.
- Warning
2 unspent outputs (400 sats) cost more to spend than they hold at typical fees.
The amount in brackets is the total of the small pieces, in satoshis. One satoshi is a hundred-millionth of a bitcoin.
What it means
The network fee is paid for the size of a transaction, so a piece of 500 satoshis costs about as much to spend as a piece of 5 bitcoin. Below a certain size the fee eats the whole piece. Dust usually comes from leftover change of an old spend, a very small payment, or a tiny deposit somebody sent to many addresses at once in the hope that the owners spend it together with other coins and so link them. See what an unspent output is.
What it does not mean
Dust is not lost. Holding an output does not itself incur a fee. It is not a sign that an address was attacked, and it does not change what the address can do with its larger pieces. The note shows the total so you can see how little it is.
What you can do
If you only watch the address, nothing. Whoever controls it can leave the dust where it is, or spend it together with larger pieces when fees are low. A tiny deposit you did not expect is best treated as noise. The transaction list shows where it came from.
Common questions
Can dust be deleted?
No. A piece of bitcoin stays on the chain until a transaction spends it. It can only be ignored or spent together with other pieces.
What counts as typical fees?
Watch uses a rough estimate of 68 virtual bytes at 4 satoshis per virtual byte: 272 satoshis. Outputs at or below that amount are counted as small. Actual spending costs depend on the address type, transaction and fee rate; this is an estimate, not a live fee quote or the network relay-policy dust limit.
Did somebody dust my address on purpose?
The chain shows a tiny deposit, not why it was sent. Some are honest tiny payments, some are sent to many addresses at once. Either way it is safe to leave it alone.