How to install an EA in MT4 (step by step, with fixes)
Copy the EA’s .ex4 file into MT4’s MQL4 › Experts folder (File › Open Data Folder), refresh the Navigator, drag the EA onto a chart, tick “Allow live trading” and switch on the AutoTrading button. When the EA’s name and a smiling face appear in the chart corner, it is running.
This guide shows how to install an EA in MT4 from start to finish, including the files that go in other folders, the settings that block trading, and what to do when the EA doesn’t appear or doesn’t trade. It takes about five minutes. Using MetaTrader 5 instead? Follow our MT5 installation guide.
Install an EA in MT4 in seven steps
- Open the data folder. In MT4, click File › Open Data Folder. This opens the folder MT4 actually reads programs from, which is not the folder MT4 was installed in.
- Copy the EA file. Open MQL4, then Experts, and paste the EA’s .ex4 (or .mq4) file there. If the EA came with indicators, put them in MQL4 › Indicators; DLL files go in MQL4 › Libraries, and set files in MQL4 › Presets.
- Refresh the Navigator. Back in MT4, open the Navigator (Ctrl+N), right-click Expert Advisors and choose Refresh, or simply restart MT4. The EA now appears in the list.
- Allow automated trading. Open Tools › Options (Ctrl+O), go to the Expert Advisors tab and tick Allow automated trading. Tick Allow DLL imports only if the EA needs it and you trust the source, and add any web addresses the EA uses under Allow WebRequest for listed URL.
- Attach the EA to a chart. Open a chart of the symbol and timeframe the EA is designed for, then drag the EA from the Navigator onto it. In the window that opens, tick Allow live trading on the Common tab.
- Set the inputs. On the Inputs tab, set lot size or risk, or click Load to apply a set file. Our guide to set files explains what each one contains. Click OK.
- Switch on AutoTrading. Click the AutoTrading button on the toolbar so it turns green. The EA’s name and a smiling face in the top-right corner of the chart show it is running.
Tip: MT4 runs one EA per chart. To run the same EA on three symbols, open three charts and attach it to each one.
Check that the EA is really working
- Experts tab. Open the Terminal window (Ctrl+T) and look at the Experts tab. Most EAs log a message when they start and whenever they skip a trade.
- Journal tab. Shows connection problems, rejected orders and the reasons for them.
- The chart corner. A frowning face means automated trading is blocked, either by the AutoTrading button or the Allow live trading box.
- The account. Make sure you logged in with your trading (master) password. The investor password is read-only and can’t place trades.
Common problems and fixes
| Problem | Likely cause | Fix |
|---|---|---|
| EA not in the Navigator | File copied to the installation folder, or it’s an MT5 (.ex5) file | Use File › Open Data Folder › MQL4 › Experts, then Refresh |
| Frowning face on the chart | AutoTrading off, or Allow live trading unticked | Turn on AutoTrading; press F7 on the chart and tick the box |
| “DLL calls are not allowed” | DLL imports blocked | Allow DLL imports in the EA’s Common tab, if you trust it |
| Running but no trades | Symbol suffix, spread filter, trading hours or lot size below the minimum | Read the Experts tab; see our EA not opening trades guide |
| WebRequest errors | The EA’s web address isn’t allowed | Add it in Tools › Options › Expert Advisors |
| Stops trading overnight | Computer slept or MT4 closed | Run MT4 on a VPS |
Updating or removing an EA
To update, close the chart or remove the EA (right-click the chart › Expert Advisors › Remove), replace the file in MQL4 › Experts, refresh the Navigator and attach it again. Note your inputs first, or save them as a set file, because a new version may reset them.
Keep MT4 running 24 hours a day
An EA only trades while MT4 is open and connected. If your computer sleeps, restarts or loses its connection, the EA stops. A VPS (a remote Windows server close to your broker) solves that; compare prices and locations in our forex VPS guide. Not sure whether to stay on MT4 at all? See MT4 vs MT5 for expert advisors.
MT4 installation FAQ
Where do I put EA files in MT4?
In the data folder: File › Open Data Folder › MQL4 › Experts. Indicators go in MQL4 › Indicators and DLLs in MQL4 › Libraries.
Why is my EA not showing in MT4?
Usually it’s in the wrong folder, it’s an MT5 file, or the Navigator hasn’t been refreshed. Copy it into MQL4 › Experts inside the data folder and right-click Expert Advisors › Refresh.
Can I run more than one EA in MT4?
Yes, one per chart. Open a separate chart for each EA or symbol. Check that the EAs use different magic numbers so they don’t manage each other’s trades.
Does MT4 need to stay open for the EA to trade?
Yes. The EA runs inside the terminal, so it stops when MT4 closes or loses its connection. That’s why most EA traders use a VPS.
Can I install an MT5 EA in MT4?
No. MT4 only runs .ex4 and .mq4 files. You need a version of the EA written for MT4.
Risk warning. Trading forex and CFDs on margin carries a high risk of losing money. Test any EA on a demo account before running it live.
Sources, checked 6 November 2026: MT4 File menu · MT4 Navigator · MT4 Expert Advisor settings · Launching an EA in MT4