Is it transaction free on Decentralized Exchanges?
No, for most cases.
TLDR;
Decentralized exchanges (DEX) has been a heated topic. DEX allow counterparties to find each other and trade directly on-chain, without depending on a centralized trading exchange. Therefore, we avoid moving your crypto into exchanges and facing the risk of a theft or runaway.
As a small fish, the next question come out of my mind is the transaction fee for DEX. Is it no transaction fee on DEX? The quick answer is no.

For example, based on a recent transaction on DDEX, it charges for 14.9% for a small amount of transaction. However, the trading fee stated in website 0.05%, without mentioning the minimum transaction fee. Based on this case, the minimum transaction fee is $0.48 for DDEX.

It’s better to be stated on the website or the announcement just as other centralized exchanges.
To sum up, DEX is more secure compared with centralized exchange, but it does not mean it’s free.
