How to install a custom indicator in MetaTrader 4
Install an MT4 indicator on desktop: use MQL4\Indicators, compile .mq4 source in MetaEditor, refresh Navigator and test it on a demo chart.
Start here
The short version: on desktop MT4, open File → Open Data Folder, put .mq4 or .ex4 in MQL4\Indicators, compile .mq4 source in MetaEditor, refresh Navigator and attach the indicator to a demo chart. MT5 files do not run in MT4.
Need a different workspace? Install a custom indicator in MT5 or Set up TradingView for practice.
MT4 and MT5 files are different.
Readable MT4 source normally ends in .mq4 and compiled MT4 output ends in .ex4. MetaTrader 5 uses .mq5 and .ex5. The languages and platform APIs differ, so renaming an MT5 file does not port it to MT4.
For six WickAtlas indicators, the download centre now provides a separate .mq4 port alongside .mq5 and Pine source. Choose the .mq4 file, inspect it and compile it in MT4 MetaEditor; never create an MT4 file by changing an .mq5 extension.
Let MT4 show you its data folder.
In the desktop terminal choose File, then Open Data Folder. Open MQL4 and then Indicators. Copy the .mq4 or .ex4 file into that Indicators folder rather than guessing where the broker installed the program.
If you use more than one broker terminal, repeat this check inside the terminal you actually plan to use. Each installation can have a different data folder.
An .mq4 file must compile cleanly.
Open an .mq4 file in MetaEditor and compile it. Read the errors and warnings rather than assuming that an old file remains compatible with the current terminal build.
Use File, then Compile, or the Compile button. MetaTrader 4's help also documents F9 for this version of MetaEditor. Successful compilation creates or refreshes the .ex4 output; return to MT4 and refresh Navigator or restart the terminal.
Recreate the lesson, not just the indicator name.
Drag the indicator from Navigator onto a demo chart. Match the timeframe, period, price input, smoothing method and levels stated in the WickAtlas lesson. Save the settings as a chart template only after checking them.
Two charts can differ because broker candles, server time, spread and history differ. Compare closed candles and write down the feed and timezone used.
Desktop files do not install in the standard MT4 mobile app.
The .mq4 and .ex4 workflow applies to the desktop terminal. The standard MT4 apps for iPhone, iPad and Android provide their own built-in analysis tools but do not load ordinary desktop custom-indicator files.
Seeing the same trading account on a phone does not reproduce a custom desktop chart. Keep the desktop terminal available for that indicator, or rebuild the idea with supported mobile drawing tools and built-ins.
Treat every custom file as untrusted until checked.
Inspect source when it is available, question unexplained DLL imports or external calls, and observe how the indicator behaves as new candles form. Remove it if its permissions or behaviour do not match its description.
Use a demo account for installation and practice. A display that looks correct is not evidence that a strategy is profitable or that a signal will remain fixed.
- Correct .mq4 or .ex4 file
- Correct MT4 data folder
- MQL4/Indicators, not MQL5/Indicators
- Clean compile
- Settings matched to the lesson
- Closed-candle and demo verification
Match the symptom to the next check
| What you see | Check first | What to do next |
|---|---|---|
| The indicator is missing from Navigator | Open the Data Folder from the broker terminal you are using. Confirm MQL4\Indicators and the real .mq4 or .ex4 extension. | Compile source, refresh Custom Indicators in Navigator and restart MT4 if the list still has not updated. |
| The .mq4 file is present but will not attach | Compile it in MetaEditor and read the errors. A failed compile cannot produce working .ex4 executable code. | Resolve the errors, compile again, then confirm the .ex4 exists before returning to MT4. |
| It attaches but the display is blank or different | Match the pair, timeframe, input values and price source. Check that the chart has enough history and read the Experts and Journal tabs. | Start with a clean demo chart and compare completed candles from the same broker feed and server time. |
| It asks to allow DLL imports | That permission lets code call an external library. It is not needed by every indicator and carries extra risk. | Leave DLL imports off unless the documented feature needs them and you trust both the indicator and the library. |
Platform setup FAQ
Can an MT5 indicator run in MT4?
No. MT5 uses .mq5 and .ex5 files; MT4 uses .mq4 and .ex4. The code must be ported to MQL4, compiled for MT4 and tested again.
Why does my MT4 indicator not show in Navigator?
First confirm that the file is in MQL4\Indicators inside the data folder opened by that exact MT4 terminal. Compile .mq4 source, refresh Navigator and inspect MetaEditor or the Experts journal for errors.
Can I install a custom MT4 indicator on mobile?
The .mq4 and .ex4 workflow is for desktop MT4. The official mobile apps have built-in indicators, but they do not provide the desktop MetaEditor file-install workflow.
Checked against the platform owner
These instructions were checked against current official help pages on 13 August 2026. Platform features can change, so use these links if a menu or limitation has moved.