Base Swap Failed? Check the Cause Before You Retry
A failed Base swap may be pending, reverted or based on a stale quote. Check its transaction status, error, balance and token allowance before you retry.
2 min read
When a Base swap fails, check its transaction status and error before submitting another transaction. A wallet or app timeout does not prove the transaction failed on-chain, and a second submission could create another trade if the first one went through.
How do you tell whether a Base swap failed?
Check the transaction hash in your wallet or on a Base block explorer: a pending status means the network has not confirmed the result, while a failed receipt means the transaction reverted. A reverted swap does not transfer the output tokens, but it can still use ETH for network fees.
If there is no transaction hash, the wallet may have rejected the request before broadcasting it. For background on the pool and pricing mechanics behind a swap, read how BaseSwap swaps and liquidity work.
What causes a Base swap to revert?
A quote can expire as pool prices or available liquidity change, leaving the transaction’s minimum output unmet. A large trade against a shallow pool can also move the price enough to push the output below that minimum.
Other common causes are too little of the input token, insufficient token allowance for the swap contract, or too little ETH in the wallet to cover network fees. The wallet’s error and the transaction receipt can help distinguish these cases.
What should you check before retrying?
Fix the cause first, then refresh the quote and confirm the amount you will receive. If the trade is still pending, check its status before sending another transaction.
- Confirm whether the transaction is pending, confirmed or reverted.
- Check the input token balance and ETH available for network fees.
- Check that the token allowance covers the intended swap amount.
- Review the refreshed quote and minimum output before approving a retry.
Slippage settings can allow a wider range of execution prices, but that can also mean receiving less than the latest quote suggested. Retry only when the refreshed terms are acceptable and the original transaction’s status is clear.