Practice the Windows Command Prompt, safely, in your browser

A pretend C: drive, a real-feeling cmd.exe, and seventeen short chapters of quests. Break anything you like; nothing here touches your computer.

COMMAND LINE CODEX// a wizard's guide to the Windows command line
0/54 quests complete
C:\Codex\cmd.exesandbox · nothing here touches your real PC
Command Line Codex practice shell [Version 1.0]
A safe sandbox: every file here is pretend, so experiment freely.
 
Type HELP for the list of commands, or pick a chapter to begin.
 
history
Untitled - Notepadpractice Notepad · Ctrl+S saves
17 chapters · 54 quests

Learn it by doing, one chapter at a time

Each chapter is a few minutes long: two short paragraphs, the commands to try, and quests that tick themselves off as you go.

help

Every command the shell understands

Each one links to its card in the Command Codex: what it does, its switches, and a practice line.

Questions

About the practice shell

Is this a real Command Prompt?

No. It is a simulator that runs in your browser and behaves like Windows cmd.exe: the same commands, the same output, the same error messages. Underneath is a pretend C: drive, so nothing you type can reach your real files.

Can it break my computer?

It cannot. Delete everything, empty your PATH, schedule a shutdown: it all happens inside the sandbox. The reset button puts the sandbox back to how it started.

Which commands does it understand?

About 54 of them: every command taught in Wizard's Guide to the Command Line, including cd, dir, copy, move, del, find, findstr, sort, fc, tasklist, taskkill, set and setx, plus pipes, redirection, && and ||, %VARIABLES% and batch files. Anything else points you to its card in the Command Codex.

Does it save my progress?

Yes, in this browser only. Your files, command history and finished quests are still there when you come back on the same device. Nothing is sent to a server.

Is it free?

Completely. The practice shell and the Command Codex are both free to use. If you would like a printed copy, Wizard's Guide to the Command Line is the book it all comes from.