Glossary
MQL4
MQL4 is the programming language used to build Expert Advisors and custom indicators for MetaTrader 4.
MQL4 (MetaQuotes Language 4) is the programming language for MetaTrader 4. It’s used to write Expert Advisors (automated strategies), custom indicators, and scripts. The code runs inside MT4 and can read prices, calculate signals, and send orders.
You don’t need MQL4 to run an EA or indicator — only to build or modify one. MT4’s MetaEditor is where the code is written and compiled into the .ex4 files the platform runs.
MQL4 is specific to MT4; MetaTrader 5 uses the newer, incompatible MQL5 — see MT4 vs MT5.
Related terms
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