The convert button is the most expensive button on your exchange. Here is how to measure it.

[feeedge]

A pattern from the fee threads here: everyone compares trading fees, most people have looked at withdrawal fees, and almost nobody has ever measured what the convert button costs. That button is where the quiet money goes.

The mechanics. Trading fees are printed on a fee schedule. Withdrawal fees are printed on a withdrawal page. The convert quote is neither: it is a spread baked directly into the price you are shown. The venue quotes you a rate slightly worse than the order book midpoint, pockets the difference, and shows you no fee line item at all. Many venues market this as "zero fee conversion," which is technically true and practically meaningless, because the fee moved inside the price.

Typical gaps, as snapshots not live quotes: on major pairs the convert quote often sits half a percent to two percent worse than the book mid. On thinner pairs it gets uglier. Someone in the withdrawal fee thread mentioned XRP to stablecoin conversions costing more than the withdrawal itself, and that matches the math: on a 1000 dollar conversion, a one percent hidden spread is 10 dollars, more than the trading fee and the withdrawal fee on the same trip combined. And since it is a percentage, it scales with size. The bigger your conversion, the more generous you are being.

The 30 second test, doable on any venue right now:
1. Open the convert screen and get a quote for a round amount, say 1000 usdt worth.
2. Open the order book for the same pair and note the mid price.
3. The difference between what convert gives you and what the mid says you should get is your real fee. Write it down as a percentage.

Repeat across two or three venues and the pattern shows itself fast. Some venues quote tight, half a percent on liquid pairs. Others quote like they assume you will never check.

Two honest exceptions. For dust and tiny balances, convert is often the only sensible route, the book does not care about your 3 dollars. And on genuinely illiquid pairs, a market order on the book can slip more than the convert spread, so the button occasionally wins. The point is not that convert is always bad. The point is that nobody checks, and the pricing reflects that.

Curious what people here find. Run the test on your main venue and post the pair, the quoted rate, and the book mid. I will tell you if your quote is fair or if your exchange is billing you for the convenience of not thinking.

[retaur]

Comparatively dexes followed by limit orders on cexes are always the cheapest rate usually.

There are some conversions between stable coins that are fee free on a lot of exchanges too now. It's crypto to crypto where conversions are costly.

[Perfectbaby]

Withdrawal fees and trading fees we are not really looking into these little cases that is where most issues are coming from us, when you take a look at how productive are they doing you would understand we should seat up to clear some kind of problem in the country. You know, both essential to be talked and handle out, another thing  here you must usually note what you should be dishing out to someone when you don’t know.

[Charles-Tim]

Two honest exceptions. For dust and tiny balances, convert is often the only sensible route

What the exchanges want you to believe by making it like that.

There are some conversions between stable coins that are fee free on a lot of exchanges too now. It's crypto to crypto where conversions are costly.

You are referring to spot trading part of the exchanges. Some exchanges still say convert is free, although shady on some exchanges but truly free on some, but which may not continue.

USDC/USDT is of zero trading fee on many exchanges, I mean on the spot trading. I am not referring to convert.