MetaTrader 4 vs MetaTrader 5

MetaTrader 4 and MetaTrader 5 share a brand and a visual interface, but they are not the same platform. MT4 is a forex-and-CFDs platform with a procedural scripting language (MQL4) and a 20-year legacy ecosystem of Expert Advisors. MT5 is a multi-asset platform with an object-oriented language (MQL5), a materially better backtester, and support for stocks, futures, and options alongside forex. The critical point almost every tutorial glosses over: MT4 EAs do not run on MT5. No investment advice, no affiliate links — neutral comparisons for researchers choosing their stack.

Head-to-Head Comparison

Both platforms are distributed free by MetaQuotes and licensed to brokers. Cost means broker-side commission and spread structure, not a platform subscription fee.

Five Points of Nuance

1. MT4 EAs do not run on MT5 — migration requires a full rewrite

This is the most consequential architectural difference. An Expert Advisor written in MQL4 does not compile in MT5, let alone run. MQL4 is procedural; MQL5 is object-oriented. Their event handling models differ: MQL4 uses a flat function model with global state; MQL5 uses event handlers in C++-style classes. The order management systems differ: MT4 uses a simple position model; MT5 introduces positions, orders, and deals as distinct entities. Moving an existing MT4 EA to MT5 is a rewrite, not a port. Budget full development time for each EA you want on MT5. If your EA catalog is large, this is a significant migration project.

2. MT5 is not "MetaTrader 4 v2" — they are different platforms

MetaTrader 5 was released in 2010, four years after MT4, and was designed as a new platform with a different architecture rather than an upgrade. MetaQuotes intended MT5 to serve multi-asset institutional clients, while MT4 served the retail forex market. The two platforms have coexisted for 15+ years, and MT4 has retained market share in retail forex because of its entrenched EA ecosystem, not because of technical superiority. Treating MT5 as a superset of MT4 with everything working is a common and expensive mistake. Verify MT4-era features specifically in MT5 before assuming compatibility.

3. Backtesting quality gap: single-symbol bar vs multi-currency real-tick

MT4's Strategy Tester runs a single symbol at a time and at bar resolution. It does not support tick-level replay or multi-currency portfolio testing. MT5's Strategy Tester supports multi-currency portfolio testing (running a strategy across multiple correlated symbols simultaneously), real-tick mode (using actual tick data from your broker's server, not synthesized ticks from OHLC bars), and cloud-distributed parameter optimization. For strategies where intrabar moves affect entries and exits, MT4's bar-level Tester will produce optimistic results that MT5's real-tick mode would reject. For portfolio-level currency strategies that hedge across multiple pairs, MT4's single-symbol constraint is a structural limitation.

4. MT4 broker proliferation: legacy dominance, not technical preference

MT4 remains the most widely offered retail forex platform because of ecosystem inertia, not because it is better. Brokers built their back-office infrastructure, customer service processes, and EA marketplaces around MT4 over 20 years. Migrating a broker to MT5 is expensive and disrupts existing retail clients who have MT4 EAs running. The practical consequence: if you are choosing a forex broker and find that MT4 has better availability or a larger EA library at that broker, that is a legitimate reason to use MT4 — not because MT4 is superior, but because the ecosystem at that broker is. Check each broker's offering independently; the best MT5 brokers for multi-asset are different from the best MT4 forex brokers.

5. Hedging mode: a historical MT5 limitation that still generates confusion

In MT5's initial release, MetaQuotes implemented a "netting" position mode only — you could not hold a long and short position on the same symbol simultaneously. This was a deliberate design choice for multi-asset compatibility, but it broke many MQL4 hedging strategies and was a significant objection from the forex community. MetaQuotes added hedging mode to MT5 later, making it optional per broker account. As of 2026, MT5 supports both netting and hedging modes, but you need to confirm which mode your broker's MT5 account uses. If you have MQL4 EAs that rely on simultaneous long/short positions, verify hedging mode is available on the MT5 account before migrating.

Best for Whom

• Maintaining existing MQL4 EAs: Stay on MT4. The rewrite cost is not justified unless you specifically need MT5's multi-asset or backtesting features.
• Broker offers MT4 only or has the best MT4 EA marketplace: MT4. Pragmatic choice; the platform is not going away.
• New EA development, forex + other asset classes: MT5. MQL5 is the modern standard; better backtesting; multi-asset support.
• Improving backtest accuracy for existing strategies: MT5. Real-tick mode and multi-currency testing produce more realistic results than MT4's bar-level Strategy Tester.

When Neither Fits

For US equities, ETFs, or US options via algo trading, MetaTrader (even MT5) is not well-suited — MT5's equities coverage depends on broker and is primarily aimed at European/Russian brokers with equities products; for US stock algo trading, LEAN/QuantConnect or Alpaca are the standard paths. For futures with tick-level backtesting and native C# scripting, NinjaTrader is more appropriate than either MetaTrader platform — see TradingView vs NinjaTrader. For Python-first code-first strategies across multiple asset classes, QuantConnect/LEAN (Apache-2.0, multi-asset, multi-broker) is a more flexible framework than any proprietary-scripted platform.