Before choosing a multi-hop route, compare its expected output with a direct route, because every pool can charge a fee on the amount passed to the next pool. A multi-hop route swaps through two or more token pairs to reach a token that has no direct pool with your starting token, or to find a better price. On Base, a decentralized exchange such as base swap uses pools to make these trades. The key is to compare the amount you receive after all the hops, not to count hops alone.
A multi-hop route passes each pool’s output forward
A hop is one swap in one liquidity pool. For example, a route from Token A to Token C might trade A for B in one pool, then B for C in another. The B received from the first pool becomes the input to the second.
An automated market maker (AMM) prices a swap using the tokens held in its pool. In a common design, the pool follows a constant-product rule: the two reserve amounts multiplied together stay roughly constant as traders swap. A trade changes those reserves, so the price moves as the trade progresses. Each pool in a route has its own reserves and fee.
Each pool fee reduces the amount available at the next hop
A pool fee applies separately at each hop. In a common AMM design, the fee is taken into account before the pool calculates how much output to return; the fee portion stays with the pool. The next hop then applies its own fee to the smaller amount it receives.
For a simple example, suppose a route crosses three pools, each charging an illustrative 0.30% fee. Ignoring price movement, each hop passes on 99.70% of its input, so the fraction left after three hops is 0.997 × 0.997 × 0.997, or about 99.10%. The combined fee effect is about 0.90%, not exactly 0.30% × 3. If pool fees differ, multiply the fractions left at each hop: (1 − fee₁) × (1 − fee₂) × …
This estimate isolates fees; it is not a full quote. Actual output also depends on each pool’s reserves and the size of your trade. A shallow pool can cause a large price change even when its fee is low.
Price impact and slippage add different costs
Price impact is the change in the pool’s price caused by your trade. It can reduce output at every hop, and it tends to be larger when your trade is big compared with a pool’s liquidity. Fee and price impact both affect the quoted output, but they describe different things: the fee is set by the pool, while price impact comes from the trade size and pool reserves.
Slippage is a limit you set for how much the received amount may worsen before the swap is rejected. It is not another pool fee. A quote may include expected fees and price impact, but the pool state can change before the trade executes, so the final amount can differ within the slippage limit.
A common mistake is to assume that a route with more hops must be worse because it pays more pool fees. The fix is to compare its final quoted output with alternatives: a deeper sequence of pools can still beat a direct swap through one shallow pool, even after its extra fees.
Compare the final output, including route costs
To choose between routes, compare how much of the token you want each route is expected to deliver for the same input. Check the number of hops and the fee charged by each pool, then consider the quoted output, which reflects the route’s fees and expected price impact. If two quotes are close, remember that more hops also mean more pool interactions, which can increase the transaction’s network cost.
Keep that network cost separate from pool fees: it pays for processing the transaction, rather than being deducted from each pool’s swap input. Its amount depends on network conditions and the work required for the route. A route with slightly higher token output may not be better overall if its additional network cost outweighs the difference.
Before swapping, check that the route ends in the token you intend to receive and that the minimum output allowed by your slippage setting is acceptable. If the route uses an unfamiliar intermediate token, make sure you understand why it appears in the path; the route’s quoted output is the practical comparison, but it does not remove the need to verify the trade.
Choose the route with the best acceptable output after pool fees, price impact, and network cost—not simply the route with the fewest hops.