MQL4 vs MQL5: Which Platform Should You Choose for Your EA?

Choosing between MetaTrader 4 (MQL4) and MetaTrader 5 (MQL5) is one of the first decisions when automating a forex or CFD strategy. The wrong choice means broker incompatibility, rewrites later, or missing features you need. Here's a practical comparison for traders hiring an EA developer in 2026.

Quick Comparison

• MQL4 — mature, huge indicator library, most retail forex brokers, simpler for basic EAs
• MQL5 — faster tester, OOP, more order types, better for multi-symbol and stocks/CFDs
• Code is not portable — MQL4 and MQL5 require separate development or conversion

When to Choose MT4 / MQL4

• Your broker only offers MT4 or your account is MT4-only
• You depend on legacy indicators or EAs available only for MT4
• Simple single-symbol forex EA with standard order types
• Your community (signals, copiers) is entirely on MT4

When to Choose MT5 / MQL5

• Broker supports MT5 with your symbols and account type (hedging/netting)
• Multi-symbol or multi-timeframe strategies on one EA
• Faster backtesting on long tick-history runs
• Stock, index, and commodity CFDs with exchange schedules
• New projects with no MT4 legacy dependency

Backtesting Differences

MT5's Strategy Tester uses multi-threading and generally handles large tick datasets faster. Both platforms can curve-fit if you optimize carelessly. Quality of results depends more on data quality, spread settings, and walk-forward discipline than on platform alone.

Can You Run Both?

Yes — many traders run MT4 for one broker and MT5 for another, or use trade copiers to bridge accounts. Developers can build the same logic twice or maintain one primary platform. TradingView webhooks can feed both MT4 and MT5 with separate parsers.

Ready to build? Read our full MT5 Expert Advisor development guide or request a quote from Nowzana.