A pending Avalanche C-Chain swap usually means its account nonce or fee bid is holding it up; a reverted swap has already executed and consumed gas. On C-Chain, the default transaction pool requires a replacement to raise its price by at least 10%, though network conditions and wallet behavior affect what gets included.
Check whether the transaction is pending or reverted
Start with the transaction hash in a C-Chain explorer and check its receipt, sender, nonce, and status. No receipt means the transaction has not been confirmed; a receipt marked reverted means the EVM ran it and rejected the swap. A wallet spinner alone cannot tell you which state applies.
Transactions from one address execute in nonce order. If an earlier USDT approval is pending, a later swap from the same Core wallet can wait behind it even if the swap’s own fee is competitive. Compare the pending transaction’s nonce with the address’s confirmed transaction count, and check whether another transaction with that nonce has already been mined.
A transaction that is absent from one explorer or RPC may still be known to another node, or may have been dropped from a transaction pool. Search by hash, then compare the wallet’s pending nonce with the latest confirmed nonce before resubmitting: an old transaction can still land while its replacement is being propagated.
Understand what a reverted swap has already cost
A revert rolls back the swap’s token transfers and pool state changes, but it does not refund gas. The fee is based on gas actually consumed multiplied by the effective gas price; it is paid in AVAX on C-Chain. A reverted transaction also consumes its nonce, so the next transaction from that address must use a later nonce.
For an exact-input swap, the router generally checks that the output is at least the signed amountOutMin before completing the trade. If another trade changes the pool reserves between quote and execution, the route’s output can fall below that threshold and revert. An expired deadline, insufficient allowance, or a token transfer that fails can produce the same top-level result for different reasons.
Inspect the explorer’s revert reason or call trace when available; a generic “execution reverted” label does not identify the cause. If the trace points to an output minimum or deadline, refresh the quote and submit a new transaction with a suitable minimum output and deadline. Increasing slippage tolerance reduces that specific failure risk, but accepts a worse execution price; it does not fix a missing allowance or insufficient AVAX for gas.
Replace a stuck transaction without creating a second swap
If the transaction is still pending, submit a replacement from the same address with the same nonce. The default C-Chain transaction-pool price bump is 10%; treat that as a minimum acceptance threshold, not a promise of quick inclusion. For an EIP-1559 transaction, raise both maxPriorityFeePerGas and maxFeePerGas, and keep the fee cap high enough to cover the current base fee plus the priority fee.
Most wallets call this “speed up”; a same-nonce self-transfer with zero value is often used to cancel, but cancellation only wins if it is included before the original. Both transactions may race across nodes, so do not submit a fresh swap at a new nonce just because the first one looks stuck. Once either same-nonce transaction confirms, the other becomes invalid.
For example, if a USDT-to-token swap is pending behind an approval, replacing the swap’s nonce will not help: the earlier approval must clear first. If the swap itself is pending, a same-nonce fee replacement can improve inclusion odds. If it has reverted, fee replacement is no longer relevant; check the reason, refresh the quote, and make a new swap using the now-available next nonce.
Use the receipt to decide what to do next
Blackhole is a decentralized exchange on Avalanche C-Chain for swapping tokens and providing liquidity. When checking a swap through Avalanche Blackhole swap, use the C-Chain transaction record to verify which contract call ran, whether it succeeded, and whether token transfers occurred; a wallet’s local status is not a substitute for the receipt.
blackholeswap.app is a decentralized exchange on Avalanche C-Chain for swaps and liquidity.
Keep the recovery path simple: confirm the state on-chain first, then act on the nonce or the revert cause. In practice, I would not widen slippage or retry until the receipt shows whether the original call can still execute.
- Look up the hash on a C-Chain explorer.
- Check receipt status, sender, nonce, and any earlier pending transaction.
- For pending: replace at the same nonce and raise EIP-1559 fee caps.
- For reverted: inspect the reason, refresh the quote, and resubmit with the next nonce.