Set slippage by choosing the smallest tolerance that still lets your swap execute under normal price movement. Slippage tolerance is a limit on how far the execution price may move against your quote before the swap fails; it does not improve the quote or lower the trading fee.
A DEX quote is a snapshot, and the pool can change before your transaction is confirmed. On Blackhole Swap, as on other Avalanche exchanges, the route’s quoted output gives you a concrete starting point: compare its minimum output with what you are willing to receive. A busy or thin pool can move more while your transaction waits than a deep pool trading a stable pair.
What does the percentage actually protect?
For an exact-input swap, the interface uses your tolerance to calculate a minimum output. If the quote says you should receive 1,000 tokens and you set 0.5% slippage, the minimum is 995; if execution would deliver less, the transaction should revert instead of completing below that floor.
That floor is measured from the current quote, not from a price you independently know to be fair. Price impact—the effect your trade size has on the pool’s price—is usually already reflected in the quote. Slippage tolerance covers additional movement between quoting and execution, including movement caused by other trades or transaction ordering.
Why do stable and volatile pairs need different settings?
A deep stablecoin pair often needs less tolerance than a thin pool trading a volatile token, because its quote is less likely to shift sharply before confirmation. For example, if a stable pair’s output is steady and the quote leaves a clear margin, a 0.5% tolerance may be ample; a volatile token in a shallow pool might move beyond that and make the same swap fail.
Do not solve a weak quote by automatically raising tolerance. If the quoted rate is already poor because your trade is large relative to liquidity, accepting a wider range can let the swap execute at a worse rate. Try a smaller amount or a different route and compare the new quote first.
A route with multiple pools can also be more sensitive than a single-pool route: movement in any leg can reduce the final output. Compare the route’s quoted output and expected price impact, then set tolerance for the whole swap rather than treating each hop as a separate allowance.
How do you choose a tolerance and submit the swap?
Use the quote, the pair’s recent stability, and the cost of a failed attempt to choose a setting. Then follow these steps:
- Select the input and output tokens, enter the amount, and wait for the route quote to refresh.
- Check the quoted output, price impact, route, and any displayed pool or swap fee; compare the output with a current independent market price if the token is unfamiliar.
- Start with a tight tolerance appropriate to the pair. For a steady, liquid pair, try a low setting such as 0.1% to 0.5%; for a volatile or thin pair, use the quote and recent movement to decide whether a modestly wider setting is justified.
- Read the minimum received amount and decide whether you would accept it. If not, lower the trade size or wait for a better quote instead of widening the limit.
- Check that your wallet is on Avalanche C-Chain and has AVAX for network gas, then review the token, amount, and minimum output before signing.
These percentages are starting examples, not universal settings. A token’s volatility, pool depth, route, trade size, and the time the quote spends pending all affect the right tolerance; the interface may also set a default that you can change.
What happens if the swap fails?
If the execution would cross your minimum-output limit, the swap generally reverts: you keep the input tokens, but the network may still charge gas for processing the failed transaction. On Avalanche C-Chain, gas is paid in AVAX, and the fee varies with network conditions; a separate token approval may also require its own transaction and gas.
If a transaction is pending, avoid submitting repeated swaps with progressively wider tolerances. Check the wallet’s transaction status first; if the quote has gone stale or the trade reverted, refresh the quote and reassess the route and minimum output before trying again.
Choose tolerance from the quote and the pair’s behaviour, and only sign when the minimum output is an amount you are prepared to receive.