Slippage

Slippage, in a swap app, is a tolerance setting. Between the moment you see a quote and the moment the transaction lands in a block, the price can change, because others are trading too. A 1 percent slippage means: execute the swap only if I get at most 1 percent fewer tokens than the quote showed. Otherwise the transaction does not go through.

With fast-moving memecoins a low slippage makes transactions fail often. A high one lets them through, but at a worse price, and invites bots to sandwich you. Slippage is not the same as price impact: price impact is the price change caused by your own order, shown in the quote in advance.