Replace a pending swap: What to know before raising gas

A pending swap is one the network has seen but not confirmed, and the fix is to replace it with the same nonce and a higher gas price — not to raise gas on a separate swap. Once the replacement confirms, the old transaction can no longer be mined.

• A nonce is the sequence number of every transaction sent from one wallet.
• Replacing a transaction means sending the same nonce again with a higher fee.
• A confirmed replacement cancels the original; a fresh transaction with a later nonce does not.
• If the network is congested, a small fee bump may not be enough.

In practice, the mechanics live in the wallet, not the DEX. Your wallet signs every outgoing transaction with an incrementing nonce, and a node will accept a replacement only if it has the same nonce and a higher fee. On an EIP-1559 network, “higher fee” can mean a higher priority fee or a higher max fee, depending on where congestion sits.

Before raising gas, open the transaction’s nonce field in your wallet and confirm what number it shows. This SpookySwap network guide walks through which networks are worth checking when swaps stall, but the core rule holds on any Ethereum-compatible chain: same nonce, higher fee, and the original swap becomes invalid once the replacement confirms.

What does “same nonce” mean in simple terms?

Every transaction from your wallet has a numbered place in line, starting at zero. If your stuck swap is nonce 7, a replacement must also be nonce 7.

The network will mine one valid nonce-7 transaction; once a replacement with a higher fee is visible, the lower-fee original tends to drop. That is how “speed up” buttons work: they build a new transaction with the same nonce, then rebroadcast it with more gas.

Why can’t I just raise gas and send the swap again?

Sending the same swap again with a higher fee will not clear the first one unless it uses the same nonce. If your wallet assigns the next nonce, the second transaction queues behind the first, and the first can still confirm at the old price.

On SpookySwap, as on any DEX, the swap transaction is a wallet-to-contract call. The DEX has no cancel button; the only cancel is on-chain, by replacing the pending item before it confirms.

What should I check before replacing?

Check the nonce, check that the replacement carries the same swap details, and make sure the new fee is actually higher. If the original is very old, it may be safer to wait for it to drop from the mempool and then send a fresh swap.

Wallets differ in how clearly they expose these controls. Some show a “speed up” option; others require manual nonce editing. The confirmed part is the mechanism; the open part is whether your wallet makes it easy.