What Is Slippage Tolerance, and How Do You Set It on a DEX?
Slippage is the gap between the price a swap quotes and the price it fills at; slippage tolerance is the most you will accept. Where slippage comes from, what to set for different tokens, where the setting lives, what to do when a swap fails on slippage, and when a token that needs high slippage is a scam.
Slippage is the difference between the price a decentralized exchange quotes when you submit a swap and the price the trade actually fills at onchain. If the interface shows 1 ETH buying 3,000 units of a token and you receive 2,980 when the transaction is included, that 0.67% gap is slippage. Slippage tolerance (Uniswap calls it Max slippage) is the ceiling you set: if the fill would be worse than the quote by more than that percentage, the swap fails instead of filling at the worse price.
Why slippage happens
- Your own trade moves the price. Most DEXs are AMMs, where price comes from the ratio of two assets in a pool. Every unit you buy shifts the ratio against you, more so for larger trades and smaller pools. That part is the price impact the interface shows.
- Time passes between quote and fill. Seconds can pass before your transaction lands in a block, and other trades change the pool meanwhile. Your quote was a snapshot.
So on an active chain slippage is nearly unavoidable. Small trades of major tokens in deep pools see very little; large trades of obscure tokens in shallow pools can see a lot. Uniswap's own example: the same $10K trade moves the price far more in a $200K pool than in a $20M one.
What slippage should I set?
| Situation | Common reference | Notes |
|---|---|---|
| Large stablecoin swap in a very deep pool | About 0.05% | Uniswap's example: $100K USDC to USDT in a pool with over $10M of depth can use a tight setting, though very low settings fail more often |
| Major pairs such as ETH/USDC | 0.1%–0.5% | Usually enough for small trades in deep pools |
| Volatile or thinly traded tokens | Around 1% | Uniswap's example: a $50K pool may need 1% or more |
| Only fills at 5%, 10% or more | Stop first | Likely a transfer tax, very thin liquidity or a honeypot; see below |
Many interfaces offer Auto slippage, which picks a value from network cost and trade size. It suits most major tokens; for unfamiliar tokens, check what it actually chose.
What 0.5%, 1% and 2% actually mean
Tolerance is a ceiling, not a guaranteed loss. If a swap quotes 1,000 USDC:
- at 0.5% you receive at least about 995 USDC, or the swap fails;
- at 1%, at least about 990 USDC;
- at 2%, at least about 980 USDC.
That is the "minimum received" figure in the wallet prompt. Fills are often better, but make sure you can live with the worst case.
How to set slippage on a DEX
On most DEXs and aggregators the setting sits behind the settings icon (usually a gear) on the swap panel, labelled Slippage, Slippage tolerance or Max slippage. You can usually switch between Auto and Custom and type a percentage. It applies to the next swaps you make; check the minimum received in the wallet prompt before confirming.
Swap failed or "slippage too low": what to do
When a swap reverts because the price moved past your tolerance, your tokens stay put but the gas spent is generally not refunded. So do not retry blindly; work through this:
- Refresh the quote. In a fast market the old quote is stale.
- Check price impact. Above 1%–2%, trade a smaller amount, split it, or route through a deeper pool or an aggregator.
- Raise tolerance in small steps. For a major token in a volatile moment, about 0.5% at a time.
- Ask whether the token is the problem. An unfamiliar token that always needs high slippage usually has a transfer tax or is a honeypot.
- Check gas and congestion. A low gas setting can leave the swap waiting until the price has moved on, which also shows up as a slippage failure.
If the interface instead warns that price impact or slippage is higher than expected, your fill could be far below the market price. Reduce the size or change pools rather than clicking continue.
The risk of setting it too high
High tolerance announces that you will accept a much worse price. In a fast market you really will be filled there, and you become a target for MEV sandwich attacks: a bot sees your pending swap, buys just ahead of it to push the price up, lets you fill at the inflated price, then sells. The higher your tolerance, the more it can take. Some wallets and RPC services offer private transaction routing to reduce this; see what an RPC endpoint is.
When high slippage is a scam signal
- Transfer taxes: some tokens take a percentage on every buy or sell, which looks like fixed extra slippage. Check that the tax is disclosed and reasonable.
- Honeypots: tokens you can buy but not sell, or sell only at an extreme tax. People who cannot sell often push slippage to 50% or 90%, which just hands the tokens over. A token that only sells at extreme slippage is very likely a honeypot. See what is a honeypot token.
- Very thin liquidity: normal-sized trades cause huge price impact. Even when it is not a scam, getting in and out is expensive; see how to read a new pool.
For any unfamiliar token, test one tiny buy and one tiny sell before trading more.
Pre-swap slippage checklist
- The interface came from the official site, not a lookalike.
- Price impact is below 1%–2%, or you have reduced the size.
- Tolerance starts at the default or 0.5% and rises in small steps.
- Unfamiliar tokens pass a small buy-and-sell test.
- Large trades are split or routed through deeper liquidity.
- The minimum received in the wallet prompt is acceptable.
- Failures are diagnosed before slippage goes up.
FAQ
If I set 1% slippage, do I always lose 1%?
No. It is a ceiling; most swaps fill with far less, and anything beyond it fails.
Are slippage and gas the same?
No. Gas pays the network to execute and is usually spent whether or not the swap succeeds; slippage is the gap between quote and fill. See why failed transactions still cost gas.
Do centralized exchanges have slippage too?
Yes. A market order on Binance or OKX walks the order book and fills at worse prices if there is not enough size at the best price. A limit order fixes the price you accept, at the risk of not filling.