Explainer

Crypto Swap Fees Explained — How to Avoid the Hidden Spread

Updated June 2026 · ~4 min read

Most people compare crypto swaps by the advertised fee. That's exactly the mistake the worst services count on. The real cost of a swap is the fee plus the spread — and the spread is usually invisible. Here's how to actually tell which swap is cheapest.

The two costs hiding in every swap

Network (gas) fees apply on top, but those are roughly the same wherever you swap. The fee + spread is where services actually compete — quietly.

⚠️ "0% fee" is a red flag, not a green one. A service can charge 0% fee and still quote you a worse rate, so you receive less. You pay through the spread instead of a labeled fee. The "free" swap can be the most expensive one.

The one trick that actually works

Forget the advertised fee. Compare the amount you'll RECEIVE. Enter the same input (say, 1 ETH) on two or three services and look at the output for the destination coin. The highest output is the cheapest swap — period. This single check exposes hidden spreads instantly.

What a fair swap looks like

See the exact amount before you swap

Flake shows a flat fee and the precise output up front — no hidden spread, no account, no KYC. Plus +3% on your first swap.

Check my rate →

The amount you see is the amount you get.

FAQ

What are the real fees on a crypto swap?
The visible service fee plus the spread (the gap vs the market rate). Gas applies on top. The spread is often the biggest, least visible cost.
Why can "0% fee" be more expensive?
The cost moves into the spread — you get a worse rate and receive less, even with no labeled fee.
How do I compare swaps correctly?
Compare the amount you'd receive for the same input across services. Highest output wins.

Related: How to Swap BTC to ETH → · Swap Crypto Without KYC →