Why Did My Transaction Fail?

A failed transaction means the network received your instruction, tried to carry it out, and could not finish. It is recorded on the blockchain as a failure, the fee is charged, and the coins or tokens you were moving stay where they were. That last part is the important one: a failed transaction does not lose your money, only the fee.

Think of a taxi meter. The driver sets off, the route turns out to be blocked, and you still pay for the distance covered - but you never arrived, so nothing else changed.

Failed, or just stuck?

These look alike in a wallet and are completely different. A failed transaction has been processed and marked failed on a block explorer. A stuck transaction has not been processed at all: it sits in the queue because the fee you offered was too low, or because an earlier transaction from the same wallet has not gone through and is holding up the line. A stuck one can often be replaced or cancelled from the wallet. A failed one cannot - it is already final.

What actually causes a failure

Three things cover most of them. The gas limit was too low, so the work ran out of budget halfway and everything was undone. The contract refused - a protocol like Uniswap or Aave checks its own conditions first, and if the price moved, the permission was missing, or your balance was short, it rejects the whole thing rather than half-do it. Or the token itself behaved unusually, which happens with tokens that charge a fee on every transfer.

Read the explorer, not the wallet

Paste the transaction hash into a block explorer such as Etherscan or Solscan. It will tell you the status, the fee paid, and usually a short reason in plain text. That one line is worth more than any amount of guessing, and it is the first thing a support team will ask you for.

Keep a little of the network's own coin spare in every wallet - most failures trace back to not having it. If the failure was a token trade, why a swap fails covers the specific causes, and how to fix a swap failed error on Uniswap gives the fixes in order.