MetaTrader 4 vs MetaTrader 5

MetaQuotes released MetaTrader 4 in 2005 and MetaTrader 5in 2010. Despite the names, MT5 is not an update of MT4 — it is a separate platform written from scratch, with a different internal architecture, a different programming language and a different way of representing positions. Both have been maintained in parallel ever since, which is why the question “MT4 or MT5?” still exists more than fifteen years later.

On the surface they are nearly identical: Market Watch on the left, Navigator below it, charts in the centre, the terminal panel with trades and history at the bottom. A trader who knows one can find their way around the other in minutes. The real differences sit underneath the interface — in how orders become positions, how strategies are tested, and what code the platform can run.

Each of these rows hides practical detail. The three that change day-to-day trading the most are position accounting, the Strategy Tester and the language break between MQL4 and MQL5 — so those deserve a closer look.

MT4 has exactly one position model: every order you send opens its own ticket, and tickets coexist independently. You can be long 0.5 lots and short 0.3 lots of EUR/USD at the same time. MT5 launched with a different model — netting — in which a symbol can only ever have one aggregate position, and in 2016 it gained an optional hedging mode that restores MT4-style separate tickets. The broker fixes the mode per account; you cannot switch it per trade.

MT5 also adds two pending order types on top of MT4’s four: buy stop limit and sell stop limit, which place a limit order once a trigger price trades. For most manual forex traders this is a minor difference; for automated systems the netting/hedging distinction is the one that breaks assumptions, because an EA written for separate tickets behaves differently when its trades merge into one position.

For anyone testing expert advisors, the tester is where the platforms diverge most. MT4’s Strategy Tester runs one symbol on one CPU thread and generates its ticks by interpolating M1 bars — the familiar “every tick” model behind the 90% modelling-quality figure. It is fast to use but the price path inside each bar is a simulation.

MT5’s tester is multi-threaded, spreads optimization passes across all CPU cores (and optional remote agents), can test one EA across multiple symbols in a single pass, and can replay real tick history where the broker provides it. In practice that means portfolio and correlation strategies can only be tested honestly on MT5, and tick-sensitive strategies get far more realistic fills. How the modelling modes differ — and what they do to results — is covered in the backtest guide.

MT4 offers 9 timeframes, from M1 to monthly. MT5 offers 21, filling the gaps with charts such as M2, M10, H2 and H12. That matters less for discretionary chart-watching than for bar-based EAs and reviews that want, say, a two-hour rhythm without resampling data by hand. On both platforms candle times follow the broker’s server clock, not yours — the free server time converter translates between the two.

MT5 also ships a Depth of Market(DOM) window, because it was designed to connect to exchange-traded markets — futures and stocks — where a central order book exists. On an over-the-counter forex feed the DOM usually shows only the broker’s own liquidity, often a handful of levels or none at all, so its usefulness depends entirely on the instrument. MT4 has no comparable order book.

The deepest break between the platforms is the language. MQL5 changed the event model — MQL4’s start() became a family of handlers such as OnTick, OnInit and OnTrade— and replaced the trade API. Where MT4’s single OrderSend call covers everything, MT5 separates trade requests, executed deals and resulting positions into distinct entities, so every piece of order-management code has to be rewritten. Compiled .ex4 files simply do not load in MT5.

A 2014 update brought MQL4 syntax much closer to MQL5, but the APIs remain incompatible: porting an EA is a development project, not a recompile. The concepts do carry over — for example, tagging trades with a magic number to tell strategies apart works the same way on both platforms.

Neither platform is objectively better, and the useful question is not which one “wins” but which constraints apply to you. If your trading depends on an MQL4-only EA, the cost of porting it is the real decision. If you need multi-symbol or real-tick testing, only MT5 provides it. If you trade exchange-listed instruments, MT4 was never built for them. Most differences are switching costs in one direction and missing features in the other.