How to Set Slippage for a Token Swap

Set slippage tolerance to the most a swap can move against you before the transaction fails. A low limit can protect the rate you accept, but if the market moves beyond it while your trade waits, the swap may not go through.

The quoted rate is based on the pool when you request the swap. Another trade can change that pool before yours completes. A guide to sushiswap covers the network choice to check before trading; once on the right chain, slippage determines how much the final output can vary.

What does slippage tolerance control?

Slippage tolerance is the maximum permitted drop in the tokens you receive, measured against the quoted amount. The swap usually includes a minimum output: if the trade would deliver less than that floor, it reverts, or fails instead of completing.

For example, if a quote says you will receive 100 tokens and the tolerance is 1%, the minimum output is 99 tokens. The final amount can be lower than the quote, but it should not fall below that floor. A tighter tolerance raises the floor; a wider one lowers it.

Why can the final amount differ from the quote?

On an automated market maker, a pool holds token reserves and uses them to set the swap rate. A larger trade can shift that rate as it uses more of the available reserves. That shift is called price impact: it comes from your trade’s size relative to the pool.

Slippage is different. It is the change between the quote you saw and the rate available when your transaction executes. Other trades, price changes or a delay while the transaction waits can affect it. A swap with high price impact may have a poor quote from the start; a higher tolerance does not improve that quote. It only allows the transaction to accept a larger change before failing.

How should you choose a setting?

Start with the interface’s default and review the quoted output and minimum output before you confirm. The right tolerance depends on the token, pool liquidity and how much the rate moves while trades are pending. There is no single percentage that suits every swap.

• If the quoted output looks reasonable and the swap completes, there is no need to raise the tolerance.
• If the swap repeatedly fails, check whether the quote changed or the pool is thin before adjusting the setting.
• If you do raise it, use the smallest increase that lets the swap proceed, then check the new minimum output.

A very wide tolerance can let a swap complete at a much worse rate than the quote. Review the minimum output each time you change the setting. If it is lower than you are willing to accept, cancel and reconsider the trade rather than accepting a floor you do not want.