Slippage is the difference between the price you were quoted for a crypto trade and the price it actually executes at. On decentralized exchanges it comes from two things: price impact (your trade moving the pool’s price) and market movement between the moment you sign and the moment the transaction is included. Slippage tolerance is the maximum difference you accept; if the price moves further, the trade fails instead of filling badly.
Key Takeaways
- Slippage = quoted price vs executed price.
- Price impact depends on trade size versus pool liquidity.
- Tolerance caps how much worse a fill can be.
- Too high a tolerance invites sandwich attacks; too low causes failed trades.
Slippage vs Price Impact
| Price impact | Slippage | |
|---|---|---|
| Cause | Your trade’s size in the pool | Price impact plus market moves and other trades |
| Known before trading? | Yes, shown in the quote | Only the maximum you allow |
| How to reduce | Smaller trade, deeper pool, split routes | Lower tolerance, faster inclusion |
How to Set Slippage Tolerance
| Token type | Common starting tolerance |
|---|---|
| Stablecoin to stablecoin | 0.1%-0.3% |
| Major tokens (ETH, BTC, SOL) | 0.3%-1% |
| Volatile or thin tokens | Higher, with caution |
Aggregators often set tolerance automatically based on the route. If a trade keeps failing, increase tolerance in small steps rather than jumping to a high number.
Sandwich Attacks
On public networks, pending transactions are visible. A bot can buy just before your swap and sell right after, capturing the difference up to your tolerance. Keep tolerance as low as the trade allows and use routes or wallets with MEV protection when available.
Why Swaps Fail
A failed swap usually means the price moved beyond your tolerance, or gas was too low during a busy period. On Ethereum you still pay gas for a failed transaction; see ETH gas fees explained. Splitting large trades and choosing deeper pools reduces both slippage and failures.
Why Aggregators Help
An aggregator compares routes across many pools and can split a trade so that each pool moves less, lowering price impact. Quotes show the minimum you will receive given your tolerance. For background on how routes are chosen, see how to bridge USDT and the swap widget below. A technical explanation of slippage is in Uniswap’s docs.
