Create Your First Commented Batch File

Now that you know how to open files in a text editor, let's write a real batch file with comments. Comments keep your scripts readable and maintainable. We'll use the editor below to write directly in your browser.

Use the editor below to write a batch file with REM comments. Click ▶ Run to simulate the output, then ⬇ Download .bat to save and run it in a real terminal.

Notice: The @REM lines do not appear in the output — they are invisible comments. Only the echo lines produce output.

As your scripts grow longer, comments become essential:

@echo off
@REM # ==============================
@REM # backup.bat  —  Daily Backup
@REM # Run every morning at 8:00 AM
@REM # ==============================

@REM # Step 1: Set source and destination
SET "SRC=demo-work"
SET "DST=demo-backup"
IF NOT EXIST "%SRC%" MKDIR "%SRC%"
echo Quarterly report>"%SRC%\report.txt"

@REM # Step 2: Run the copy
echo Backing up %SRC% to %DST%...
xcopy "%SRC%" "%DST%" /s /e /i /y /q

@REM # Step 3: Confirm
echo Done! Backup complete.
PAUSE

Good comments answer:

• What the script does (the header)
• Why a particular command is used
• What each section accomplishes