How to Fix a Swap That Keeps Failing With "Insufficient Output Amount"

23 September 2026

The "insufficient output amount" error means your swap cannot execute because the final amount of tokens you would receive is less than the minimum you specified. The fix is almost always to increase your slippage tolerance, reduce the swap size, or check that the liquidity pool still holds enough of the token you want. Here is how to diagnose and resolve each cause.

What triggers this error

When you submit a swap on a DEX like MilkshakeSwap, you set a minimum amount of output tokens you are willing to accept. The smart contract checks the actual output calculated from the pool's reserves at the moment of execution. If that real output is below your minimum, the transaction reverts with "insufficient output amount" (or a similar message like "Too little received").

This is a safety feature. It prevents you from getting far fewer tokens than expected if the price moves against you between submitting and confirming the transaction.

Step 1: increase your slippage tolerance

Slippage tolerance is the percentage you allow the final price to change from the quoted price. A tight tolerance (e.g., 0.1%) is more likely to fail because even a small price movement or a larger trade can push the output below your minimum.

• Open the swap settings on MilkshakeSwap (usually a gear icon).
• Raise the slippage tolerance. Common starting values are 0.5% for stablecoin pairs and 1 - 2% for volatile tokens.
• For very small liquidity pools or tokens with low trading volume, you may need 3 - 5% or more. Be cautious - higher slippage means you accept a worse price.
• If the error persists after raising slippage to 5 - 10%, the issue is likely not slippage alone.

Step 2: reduce your swap amount

A large swap relative to the pool's size causes high price impact. The constant product formula (x * y = k) means that buying a significant portion of one token depletes the other token's reserves, driving up the price you pay. If the price impact pushes the expected output below your minimum, the swap fails.

• Try swapping a smaller amount, such as half or a quarter of your original input.
• If the smaller swap succeeds, the pool lacks sufficient depth for your original trade size.
• Consider splitting the trade into multiple smaller swaps over time, or using a DEX aggregator to route through multiple pools.

Step 3: check pool liquidity

Some tokens have very thin liquidity. If the pool's reserves are nearly drained of the token you want to receive, even a small swap can fail.

• Visit the MilkshakeSwap pool page for the pair you are using. Look at the total liquidity and the ratio of the two tokens.
• If one token's reserve is extremely low (e.g., less than 1% of the pair), the pool cannot handle meaningful swaps.
• You may need to use a different trading pair (e.g., swap to a stablecoin first, then to the desired token) or find a pool on another DEX.

Step 4: Verify Token Approvals and Allowances

You must approve the DEX to spend your input tokens before swapping. An expired or insufficient approval can cause a revert, though it usually shows a different error. Still, it is worth checking.

• On the swap page, if you see a "Not enough allowance" or "Approve" button, click it to set the approval.
• Ensure you approve a sufficient amount. Some tokens require exact approvals; others allow infinite approval. MilkshakeSwap typically requests the exact swap amount.

Step 5: Use a DEX Aggregator

If none of the above fixes the problem, the liquidity you need may be spread across multiple pools. A DEX aggregator checks several exchanges at once and splits your trade to get the best total output.

• MilkshakeSwap itself may offer an aggregator mode. Look for a "Swap via aggregator" or "Best price" toggle.
• If not, use a dedicated aggregator like 1inch or Matcha, and paste the MilkshakeSwap pool address if needed.

Step 6: check network conditions

High gas fees or network congestion can cause transactions to be mined later than expected, when the pool state has changed significantly. This is less common but possible.

• Increase your gas price (priority fee) to get faster confirmation. On MilkshakeSwap, you can adjust this in the transaction settings.
• Wait for a period of lower network activity, then retry.

When the error persists

If you have tried higher slippage, smaller amounts, and aggregators, and the swap still fails, the token or pool may have a fundamental problem. Common issues include:

• Fees on transfer: Some tokens charge a fee on every transfer (e.g., 1 - 5%). This reduces the amount that actually reaches the pool, causing the output to fall below your minimum. You may need to set slippage higher than the fee percentage.
• Tax tokens: Similar to fees, but applied at the contract level. Research the token's mechanics before trading.
• Blacklisted or paused contracts: The token contract may have restrictions that prevent certain addresses from trading. This is rare but possible.

In such cases, consider whether the trade is worth the risk. If you cannot swap a token out, you may be stuck holding it. Proceed only if you understand the token's rules and accept the possibility of losing your input entirely.

Back to dex swaps