MetaTrader 4, most often referred to as just MT4, has been the go-to trading platform for the retail forex trading community for over a decade, and the popularity of the platform continues to this day. Although all kinds of forex brokers offer MetaTrader 4 to their traders, some certainly have lower spreads than others.
The great thing about using a well-known trading platform like MT4 is that it becomes incredibly easy to change from one broker to another, for example if a new broker offers lower spreads than the old one. Traders then get the benefit of continuing with the same platform they are already used to, while at the same time enjoying the lowest spreads and commissions that the industry has to offer.