But we can take help from CoinMarketCap, Coingecko to verify if the exchange website is real or not. Because there is always a real website link here.
Not all exchanges listed on cmc and coingecko are reputable, they are indeed real website but the chance of your funds getting locked in is higher than using those exchanges that can be seen on their top 20 exchanges based on volume. Always google the exchanges' review, either on reddit and here (bitcointalk) and other community forums, ignore those review sites since most of them are paid.