In my opinion, the exchange is good-
1. binance
2. bittrex
3. kucoin
These exchange are good, safe and easy to use.
So, did you rank these exchanges based on their customer service? Number of coins listed? Security? Faster transactions? Etc.
If I would to rank specific exchanges based on the OP's concern.
Hello i am newbie here and i am newly trader can someone give some information which exchange is the best for buying altcoins ?
I would rank them in terms of who has the lowest transaction fees. As you see the OP specified "best for buying altcoins" if you noticed that.
So, I guess kucoin and bittrex doesnt have the low transaction fee features, but neverthless, those exchange are the best so far.