Forex Education
How to Install an Expert Advisor in MT4 and MT5
To install an Expert Advisor in MT4 or MT5, put the correct platform file in the active terminal’s Experts folder, compile it only if supplied as source code, then attach it to a chart and check its trading permissions. Start on a broker demo account. The checks below help you confirm that the intended EA has loaded with the intended settings, without mistaking a chart icon for proof that the strategy works.
Quick answer: MT4 uses EX4 files in MQL4/Experts; MT5 uses EX5 files in MQL5/Experts. Open the destination through File > Open Data Folder. Check both the platform-wide trading switch and the EA’s own permission. Keep DLL imports and WebRequest disabled unless a reviewed, trusted dependency needs them.
This desktop guide uses relative folder paths. Follow the developer’s installer or activation instructions where they differ. For background, read the AutoPipShop guide to Expert Advisors.
Choose the correct file and installation route
Gather the download, manual, licence instructions and any supplied settings file. Extract archives first. EX4 and EX5 files are executables: programs MetaTrader runs. MQ4 and MQ5 are source files that need compilation to create an executable. See the MetaEditor compilation documentation.
| Installation detail | MT4 | MT5 |
|---|---|---|
| Ready-to-run EA file | EX4 | EX5 |
| Main source file, if supplied | MQ4 | MQ5 |
| EA destination inside the data folder | MQL4/Experts | MQL5/Experts |
| Compilation command for source | Compile / F7 in MetaEditor | Compile / F7 in MetaEditor |
| Individual trading permission | Allow live trading | Allow Auto Trading |
| Chart status to inspect | EA name and smiley status | EA name and status icon |
MetaQuotes documents these destinations in its MT4 data-folder guide and MT5 file structure. Use the developer’s build for your platform. Renaming EX4 to EX5 cannot perform the code changes and compilation involved in moving an MQL4 program to MQL5.
For an MQL5 Market purchase, use the relevant MQL5 account and the platform’s purchase/installation controls. A free Market EA demo is restricted to Strategy Tester; it cannot run on an online chart, even with a broker demo account. Check the official Market installation and demo rules before treating that restriction as a fault.
Complete the installation in the intended terminal
If you have several broker terminals, record which one you are changing before following this checklist.
- Sign in to the intended broker demo account with trading access. Check the account identity before enabling automated trading.
- Open File > Open Data Folder from that terminal. Enter MQL4/Experts for MT4 or MQL5/Experts for MT5.
- Copy the matching EA file there. Place accompanying indicators, includes or libraries in their documented destinations; do not put every downloaded file into Experts.
- Compile the main source file if source is the intended delivery. Skip compilation when the developer supplied a ready-to-run EX4 or EX5.
- Open Navigator and locate the EA. Refresh the program list if offered, or save your work and reopen the demo terminal after checking the file and folder.
- Open the symbol and timeframe specified by the developer, attach the EA, then review its inputs and load the matching preset if supplied.
- Check the EA’s individual trade permission and the platform-wide switch. Review any requested outside-library or website access separately.
- Read the initialisation messages, inspect the chart status and record the starting settings. Observe the documented behaviour on demo before considering a live setup.
A broker demo account uses training funds, but an investor login is read-only. Use trading access for execution checks; the MT4 label Allow live trading does not turn a demo account into a real-money account. MetaQuotes explains demo-account operation and the restrictions of investor access in MT4 and MT5.
Check the data folder and compile source only when needed
Open the folder from the target terminal instead of guessing a location under Program Files. Keep a note of the destination alongside the download so you can retrace the change.
For source delivery, open MetaEditor from the target terminal, open the main source file and select Compile or press F7. Errors prevent executable output; warnings can accompany output and still deserve review. Send failed compilation messages to the developer and request a compatible build.
In MT5, F4 opens MetaEditor, and an MQ5 file alone does not appear as a runnable EA in Navigator. The official source-installation instructions explain this extra step. In MT4, open Navigator through View > Navigator or Ctrl+N, as described in the Navigator guide. A grey list icon alone is not a sufficient diagnosis of a broken vendor executable.
Attach the EA and preserve the starting inputs
Use a clean chart for the first demo run. MetaTrader permits one EA per chart; attaching another replaces the existing chart EA. Choose the documented symbol and timeframe. Some EAs manage several symbols from one chart, so ask the developer if the scope is unclear.
Drag the EA from Navigator onto the chart and inspect its properties. A SET preset contains input values, not the trading program. Use Inputs and Load for the appropriate preset, then check the values against the manual and save your starting configuration. Do not assume a preset from another release is suitable. The platform controls are covered in the MT4 launch guide and MT5 EA properties guide.
Record the EA version, preset filename and any values you changed. This gives support a precise starting point.
Enable the required permissions and inspect the status
Check the global automated-trading control and the individual EA setting. Global permission can block trades while the EA continues analytical work. MT4 uses Allow live trading; MT5 documentation uses Allow Auto Trading. Inspect the control in your build.
Keep the protective options that disable trading after selected account, profile or chart changes unless you have a specific reason to change them. Recheck permission after such a change. MetaQuotes describes these controls in the MT4 EA settings and MT5 platform settings.
DLL imports let a program call an outside software library. WebRequest lets it contact explicitly permitted website addresses. Leave both off unless the trusted developer documents the dependency and you have reviewed why it is needed. If access is justified, permit only the required dependency or exact trusted addresses.
Inspect the EA name and status in the chart corner. MT4’s smiley and MT5’s status icon are platform-specific indicators, not evidence of profitability or a promise of an immediate order. Confirm the account and settings as well as the icon.
Verify initialisation and route the first failure
Read Experts for the EA’s messages. In MT5, also use Journal for terminal events such as connection activity; MT4’s Experts tab records EA messages and operations. Copy the relevant dated lines rather than a single unexplained error number. See the MT4 Experts log reference and MT5 logging guide.
| What you observe | First check |
|---|---|
| EA absent from Navigator | Target terminal, platform file, active folder and compilation result |
| Attached but trading blocked | Global switch, individual permission and account access |
| Dependency or licence message | The exact log text against the developer’s instructions |
| Loaded with no order | Whether the documented trading conditions occurred; do not force a signal |
For installation support, collect the platform/build, EA version, symbol, timeframe, preset and a dated log excerpt. Remove credentials and unnecessary account details before using AutoPipShop’s contact page. State which step failed.
When the EA loads and its configuration is understood, continue demo observation under its documented rules. Historical testing is a separate check using past data, as the MetaTrader Strategy Tester documentation explains. Use our EA backtesting guide for that next task. Successful installation alone does not establish that a strategy will make money.
Source check: Prepared for AutoPipShop from MetaQuotes documentation checked on 9 September 2026. This is an installation guide, not a report of hands-on testing of a particular EA.
Frequently asked questions
Which folder should I put an EA in?
Use File > Open Data Folder in the intended terminal, then MQL4/Experts for MT4 or MQL5/Experts for MT5. Companion files may need different destinations.
Do I need to compile an EX4 or EX5 file?
No. Those are executable files. Compile the main MQ4 or MQ5 source only when that is the developer’s intended delivery. A supplied executable does not need accompanying source.
Why does the EA not appear in Navigator?
Check the terminal’s data folder and the platform file. For source delivery, inspect compilation first. Then refresh the list if available or reopen the demo terminal; repeated copying will not fix an incompatible file.
Should I enable DLL imports for every EA?
No. Keep DLL imports off unless a trusted, documented dependency requires them. Review WebRequest separately and permit only the specific trusted addresses required by the EA.
Why will a Market demo EA not run on my demo-account chart?
The product demo has its own restriction: MQL5 Market EA demos run in Strategy Tester, not on online charts. A broker demo account changes the funds used for trading; it does not remove the Market product restriction.