Tx Doctor / EVM error library / Slippage exceeded on a swap
EVM error: Slippage exceeded on a swap (INSUFFICIENT_OUTPUT_AMOUNT)
The pool returned less than your minimum output (or took more than your maximum input), so the router reverted instead of filling at a worse price.
Why it happens
- The price moved between quote and execution — normal on volatile pairs and large orders.
- Someone else's trade landed first and moved the pool (including sandwich attacks).
- The slippage tolerance was left at the default 0.1–0.5% on a thin pair.
- A tax/fee-on-transfer token reduced the amount the pool actually received.
How to fix it
- Raise slippage tolerance in small steps (0.5% → 1% → 2%) and never blindly to 10%+.
- Split a large order into several smaller swaps.
- Re-quote immediately before signing so the minimum output reflects current liquidity.
- Use a private RPC / MEV protection if you keep getting front-run.
What it looks like in the wallet or explorer
UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT
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