A set file is the settings of an expert advisor saved to disk. Most EAs sold for MetaTrader come with one or more of them: a file for gold, a file for EURUSD, a “low risk” and an “aggressive” version. Loading one takes ten seconds. Understanding what it does, and what it cannot carry over from the seller's account to yours, is what this guide is for.
What a set file is
A .set file is a plain text file with one line per input of an EA or indicator, written as InputName=value. It stores everything you see on the Inputs tab when you attach the tool: lot size or risk percent, stop loss and take profit, trading hours, magic number, filters and so on. It does not contain the EA itself, a license, or anything from the Common tab such as the Allow Algo Trading tick box.
Because it is text, you can open a set file in Notepad to read the values, and you can compare two set files side by side to see exactly what a seller changed between a “safe” and a “turbo” version. Lines that start with a semicolon are comments or optimisation ranges and are ignored when loading.
Where MetaTrader keeps set files
| Platform | Set files for charts | Set files saved by the tester |
|---|---|---|
| MT5 | MQL5/Presets | MQL5/Profiles/Tester |
| MT4 | MQL4/Presets | tester (in the data folder) |
All of these live inside the data folder: open it with File, then Open Data Folder. Copying a set file into Presets is convenient because the Load dialog opens there, but it is not required; Load lets you browse to any folder, including Downloads.
How to load a set file
- Attach the EA to a chart of the symbol and timeframe the file was made for. A gold set file on a EURUSD chart will load without complaint and trade nonsense.
- In the settings window, open the Inputs tab.
- Click Load, select the
.setfile and click Open. Every input changes to the file's value. - Scroll through the list. Check the lot size or risk input against your balance with the position size calculator, and the magic number if you run several EAs on one account (each needs its own).
- Click OK. The EA restarts with the new settings.
To change the settings of an EA that is already on the chart, click the chart and press F7, or right-click the EA's name in the top right corner. If you have not installed the EA yet, start with our install guide.
How to save your own
Once the inputs are the way you want them, click Save on the Inputs tab and give the file a name that says what it is for, such as GoldEA-XAUUSD-M15-1pct.set. Save a file before you change anything on a working chart, so you can go back, and save one per symbol if the EA runs on several. Set files are the easiest way to move an EA's settings to a VPS: copy the file, load it there, done. Our VPS guide covers the rest of that move.
Set files in the strategy tester
The strategy tester has the same Load and Save buttons on its Inputs tab, so you can test exactly the settings a seller supplied before you trade them, and save the result of an optimisation as a set file to load on a live chart. MT5 saves tester files to MQL5/Profiles/Tester rather than Presets, so browse there when you load one onto a chart. The backtesting guide explains how to set up a test that reflects your broker.
A set file saved from an optimisation can contain ranges (start, step, stop) for each input as extra values on the line. Loading it on a chart uses only the first value, which is what you want.
Why a set file behaves differently at another broker
The commonest complaint about set files is “I loaded the seller's file and it does not trade like the backtest”. The settings are identical; the account is not. These are the differences that matter:
| Difference | What it changes | What to do |
|---|---|---|
| Symbol name and suffix | An EA set to trade XAUUSD may see XAUUSD.m or GOLD and never open a trade. | Use the symbol input if there is one, or attach to the chart with your broker's exact symbol. |
| Digits | Stops and grid steps in points are ten times too small or too large between 2- and 3-digit gold quotes, or 4- and 5-digit forex quotes. | Check the digits on your chart and whether the EA says its inputs are in points or pips. The pip value page explains gold points. |
| Contract size and lot step | A lot input tuned for a 100 oz gold contract is wrong on a 10 oz or 1 oz contract. | Read the symbol specification (right-click the symbol in Market Watch) and re-size. |
| Spread and commission | A scalping set file tuned for a 10-cent gold spread loses its edge at 30 cents. | Compare your typical spread with the seller's stated test conditions before trading it. |
| Server GMT offset | Time filters in the file are in the seller's server time. A different offset shifts every session window. | Look for a GMT offset input and set it to your server, or shift the trading hours by the difference. |
| Leverage and balance | Fixed lots sized for a $10,000 account at 1:500 can exceed margin on a $1,000 account at 1:30. | Switch to a risk-percent input if the EA has one, or recalculate the lot size for your balance. |
When Load does nothing
- The inputs did not change. The file was made for a different EA or a different version with renamed inputs. MetaTrader matches by input name and silently skips names it does not find. Open the file in Notepad and compare the names with the Inputs tab.
- Some inputs changed, others did not. Same cause for those inputs: a newer version added or renamed them. Set the missing ones by hand from the seller's notes.
- The file is greyed out in the dialog. It is not a
.setfile. Downloads sometimes arrive as.set.txt; rename the file so it ends in.setonly. - Values look right but the EA still does nothing. That is no longer a set file problem. Work through the EA not trading checklist, starting with Algo Trading and the Experts tab.
Checklist before you trust a set file
- Open it in Notepad and read the lot size, risk and maximum trades. Nothing in a set file is hidden.
- Load it in the strategy tester on your own broker's data and compare the result with the seller's claims. Our guide to evaluating an EA lists the numbers to look at.
- Check the symbol, digits, GMT offset and lot size against your account using the table above.
- Run it on a demo account for at least two weeks before it touches real money.
- Save your own copy once it is right, and keep the original so you can see what you changed.
Every expert advisor on this site ships with its set files where the author provides them, and the product page says which symbol and timeframe each file is for.