Your exchange, and what to switch off
You can use a mixed exchange for the halal part of what it sells, the same way you can buy bread from a shop that also sells things you avoid. What matters is what you press.
The exchange is not the ruling
No major exchange is entirely permissible, because all of them sell leverage. That does not make holding a spot balance there impermissible. The product decides the ruling, not the company's whole catalogue.
Switch these off on day one
Margin and futures permissions. Frequently enabled during account setup without you choosing them.
Auto-enrolment in Earn or Savings. Several exchanges opt you in and pay interest on idle balances by default.
Lending your assets to other users. Often buried inside a setting about growing your holdings.
Auto-conversion of small balances into the exchange's own token.
Then go and check what you are already enrolled in, rather than only what you turn on from here.
If interest has already landed
Turn off the source first, then give away the amount received without expecting any reward for giving it. It is not sadaqah and it does not count toward your zakat.
If the setting cannot be disabled at all, that is a reason to move your funds rather than a reason to accept it.
What to look for in a venue
Spot pairs for the assets you actually hold. Withdrawal to your own wallet, which is the real test of whether you own anything. No default enrolment into yield products.
Then get it off the exchange
An exchange balance is a claim on a company. That is recognised ownership, and it is weaker than holding the asset yourself, which is why the phrase about not owning your keys exists.
Moving a long term holding to a wallet you control turns a claim into possession. Do it once with a small amount first, so your first transfer is not also your largest.
One warning that costs people everything: a seed phrase nobody else can reach is not security, it is an inheritance your family cannot claim. Write it down, store it somewhere separate from the wallet, and make sure someone you trust knows it exists.
In one line: use the spot side, switch off the rest, and check what you were opted into rather than only what you opted into yourself.
Using a mixed exchange for spot is permissible. The prohibited part is the products, so the work is switching them off and checking what you were enrolled in by default.
Is your crypto exchange halal?