> For the complete documentation index, see [llms.txt](https://flowrouter.gitbook.io/flowrouter-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://flowrouter.gitbook.io/flowrouter-docs/use-flowrouter/slippage-and-fees.md).

# Slippage and fees

Understand slippage tolerance, gas, liquidity fees, and positive execution surplus.

Review the quoted output, minimum received, and estimated network fee together. They describe different parts of the swap.

## Slippage tolerance

Slippage is the difference between the quoted execution result and the result available when the transaction executes. Your tolerance sets how far below the quote the output may fall before the transaction must revert.

FlowRouter defaults to **0.5%**. Presets are **0.1%, 0.5%, 1%, and 3%**. Custom values range from **0.01% to 10%**, with up to two decimal places.

For example, if a quote is 100 tokens and its displayed minimum is 99.5 tokens, execution must return at least 99.5 tokens to complete. Use the actual **Minimum received** shown in the app, which accounts for integer token amounts.

A higher tolerance permits a larger reduction in output. A lower tolerance can cause more transactions to revert when prices move. Changing slippage does not guarantee a route or fix an unsupported token.

## Network fees

Robinhood Chain charges transaction fees in native ETH. An ERC-20 approval and a swap are separate transactions and can each incur fees.

The app's network fee is an estimate, not a fixed charge. When selling native ETH, **Max** leaves a reserve for fees rather than selecting the entire ETH balance. The final network charge depends on the executed transaction and chain conditions.

A reverted transaction can still consume gas. See Robinhood's [chain documentation](https://docs.robinhood.com/chain/connecting/) for network context.

## Pool and protocol fees

Liquidity venues can charge trading fees. Their effect is reflected in the route's quoted output; they are separate from the wallet's network fee.

The documented frontend uses referral code `4663`. This is in the router's zero-fixed-referral-fee range. It does not mean that a swap has no gas cost, no venue fees, or no surplus retention.

## Output above the quote

The current FlowRouter contract **caps the output sent to the recipient at the quoted output**. If the route produces more than that, the difference is positive execution surplus. The router retains it or distributes a configured share to a referral beneficiary.

For example, with a quote of 100 tokens and a minimum of 99.5:

| Output available after applicable router fees | Result                                               |
| --------------------------------------------- | ---------------------------------------------------- |
| 101 tokens                                    | Recipient receives 100; 1 token is positive surplus. |
| 99.8 tokens                                   | Recipient receives 99.8.                             |
| 99.4 tokens                                   | The swap reverts because the minimum is not met.     |

At the deployment snapshot recorded in [Network and contracts](/flowrouter-docs/reference/networks-and-contracts.md), referral `4663` has no configured beneficiary surplus share, so positive surplus remains with the router. Referral surplus configuration can change.