MT4 vs MT5 for Expert Advisors: Which Platform Should You Automate?
The MT4 vs MT5 decision is the first one every automated trader has to make, and it shapes everything that follows: which expert advisors you can run, how your backtests are built, and which brokers you can use. This guide compares the two platforms on the technical details that actually matter for automation — 64-bit architecture, multi-threading, tick history quality, hedging and netting accounts, EA compatibility and backtesting differences — and ends with practical guidance on when to choose each.
MT4 vs MT5: what actually changed under the hood
MetaTrader 4 launched in 2005 and was designed for a single purpose: forex trading on 32-bit, single-threaded hardware. It still serves millions of traders, but its architecture has not fundamentally changed since. MetaTrader 5, released in 2010, is a 64-bit, multi-threaded platform built from scratch. In practice that means MT5 can calculate indicators and run several charts, symbols and expert advisors in parallel without the interface freezing, and it can handle larger data volumes in the same amount of time.
The other structural difference is tick history. MT4 records ticks only from the moment you open a chart, so backtesting quality depends on the data you have personally collected. MT5 stores minute-depth tick history on the server, which means it can reconstruct realistic price behaviour for any period its brokers provide. For an automated trader this is not a minor detail — it is the difference between backtesting on modelled data and backtesting on data that resembles what live fills will look like.
MT4 vs MT5: hedging versus netting accounts
Position accounting is where the two platforms differ most for strategy logic. MT4 accounts are always hedging accounts: every trade stays separate, and you can hold both a buy and a sell in the same instrument at once. MT5 supports two account types. Netting accounts merge all positions in one instrument into a single net position with an averaged price; hedging accounts behave like MT4. The broker decides which type is offered, and the choice changes how your expert advisor must manage trades.
Grid and martingale systems, which rely on layering multiple positions, need hedging accounts. Systems that trade one position at a time can run on either, but netting changes average price and total size calculations, so an EA written for one account type will misbehave on the other. Before you choose an EA, check both the platform and the account type your broker offers. The regulatory environment matters here too: the European Securities and Markets Authority sets the CFD leverage framework that applies to retail accounts, and the Financial Conduct Authority enforces it for UK brokers, regardless of whether you trade on MT4 or MT5.
MT4 vs MT5: EA compatibility and migration
Expert advisors do not move between platforms. MT4 EAs are written in MQL4 and compiled to .ex4 files; MT5 EAs use MQL5 and produce .ex5 files. The languages differ enough that porting is a rewrite, not a conversion, and no reliable automated converter exists. This is why every AlgoTM product ships in platform-specific versions, and why you should decide on your platform before you buy anything.
Once you have decided, installation is straightforward on either platform — our step-by-step MT4 installation guide and MT5 installation guide cover downloading the file, placing it in the Experts folder, refreshing the Navigator and enabling AutoTrading. If you are not sure which version to buy, start with the guides and confirm your platform build number before checkout.
MT4 vs MT5: backtesting differences
The Strategy Tester is where MT5 pulls clearly ahead. MT4’s tester runs single-threaded and models ticks from chart time-frames, which under-represents spread variation, gaps and news spikes. MT5’s tester is multi-threaded, runs on real tick data at one-minute depth, and lets you run optimisation across multiple cores. Backtests on MT5 therefore take less time and produce results that are more representative of live trading — particularly for scalping EAs and strategies sensitive to slippage.
That does not make MT4 backtesting worthless. For swing and position strategies on higher time-frames, MT4 results are often good enough to validate an idea before moving to forward testing. But if you are building, optimising or comparing expert advisors, MT5 gives you better evidence with less effort. Whatever platform you choose, forward-testing on a demo account remains the final filter, and no backtest result should ever be treated as a promise of future performance.
MT4 vs MT5: which should you automate on
The honest answer is that most brokers settle it for you. The majority of established brokers offer both platforms, but an increasing number of newer brokers — particularly those serving prop-firm challenge accounts and crypto trading — offer MT5 only. If your preferred broker or prop firm does not support one platform, the decision is already made.
Where both are available, choose MT5 if you are starting fresh, want more accurate backtesting, trade multiple instruments, or need faster execution on modern hardware. Choose MT4 if your existing strategy is built in MQL4, if your EA catalogue is MT4-only, or if you prefer the hedging behaviour and familiar interface. If you are automating for the first time and have no legacy to protect, the AlgoTM automation hub recommends starting with MT5. Whichever you pick, note that the CFTC warns that leveraged retail trading carries significant risk — the platform does not change that.
Frequently asked questions about MT4 vs MT5
Can I run an MT4 expert advisor on MT5?
No. MT4 expert advisors are written in MQL4 and compiled to .ex4 files; MT5 uses MQL5 and .ex5 files. The two languages are not interchangeable, and an EA built for one platform will not load on the other. Migrating requires a rewrite of the source code, not a file conversion, so always buy the version that matches your chosen platform.
Does MT5 backtest more accurately than MT4?
Generally yes. The MT5 Strategy Tester works with real tick history at one-minute depth, while MT4 relies on modelled ticks built from higher time-frames. That means MT5 backtests reflect spreads, gaps and slippage more realistically. MT4 backtests can still be useful for rough validation, but MT5 results are closer to what you should expect live.
Why do so many brokers still offer MT4 if MT5 is newer?
MT4 has a huge ecosystem: years of plugins, third-party tools, documented code and trader familiarity. Many brokers also use MT4’s Gateway for connectivity and integrations. Most reputable brokers now offer both platforms, and a growing number of newer, prop-focused and crypto brokers offer MT5 only. Check your broker’s platform list before choosing.
Is a hedging or netting account better for running expert advisors?
It depends on your strategy. Hedging accounts keep each position separate, which suits grid, martingale and multi-position strategies. Netting accounts merge positions in the same instrument into one net position, which simplifies risk but changes how average price and total size are calculated. Your EA must be written for the account type you run, so match them carefully.
Ready to automate? Compare the platform requirements of every AlgoTM expert advisor on the automation hub, then follow the MT4 or MT5 installation guide to get started.
Risk disclosure: Trading foreign exchange, commodities, CFDs and cryptocurrencies carries a high level of risk and may not be suitable for all investors. Past performance is not indicative of future results. AlgoTM provides trading tools and technology only and does not provide investment advice, portfolio management or guaranteed returns.
