MQL4 Programming for MetaTrader 4 (Updated 2021)

MQL4 is an essential programming language in the field of algorithmic trading. As the native language of the MetaTrader 4 Forex trading platform, it is important to know all the details about MQL4. In this way, you can go deeper into its study in order to learn how to develop automatic trading tools.

What is MQL4?

MQL4 or MetaQuotes Language 4 is the programming language used to develop algorithmic software on the Forex trading platform MetaTrader 4 (MT4). With MQL4 you can develop various trading tools for MT4 such as automated trading robots, Expert Advisors (EAs), financial market indicators, among other Forex trading tools. MQL4 was launched in 2005 by the company MetaQuotes and, since then, it is one of the world reference programming languages in algorithmic trading.

What language is MQL4 based on?

MQL4 is based on C++, so it uses many of the basic concepts of this programming language such as object-oriented programming. This does not mean that a coder with knowledge of C++ can develop applications in MQL4. However, the learning curve will be much easier compared to people without previous programming experience.

What is the difference between MQL4 and MQL5?

Although both MQL4 and MQL5 are based on C++, until build 600 of MetaTrader terminal, MQL4 was a language more basic and elemental than MQL5. However, starting from that build hardly any differences are between them. In fact, both MQL4 and MQL5 have not been fully merged mainly because of the vast number of programs developed over MQL4, which are incompatible with MQL5. So currently, MQL4 programming and MQL5 programming are basically the same with just some small differences.