1.3 Tour of CodeSandbox.io

Watch the video course


What you'll learn:

  • Setting up and customizing CodeSandbox.io
  • Forking and Github


CodeSandbox is a popular online code editor, so we don't have to download anything! In the past, we’d have to do a lot of complicated setup on our computers to get things going, but with CodeSandbox, all we need is a browser!

codesandbox image

Set Up

  1. Click create Sandbox on the top right

    CodeSandbox gives us a list of templates to choose from.

  2. Press React since we are going to create a React application

    In this interface on the left, we have a list of directories and files that this project consists of.

    codesandbox index.js

  3. Done!


Folding the Pane

We can click this icon to fold the left pane.

codesandbox close icon

Or this icon eventually to fold the pane.

codesandbox close icon

Code Preferences

Now I have the source code on the left, and a preview of the code on the right.

  1. Colour theme

    File --> preferences --> settings --> type theme in the search bar --> choose any you like!

    If you would like the classic theme from framer, go to this website https://github.com/framer/syntax --> click themes --> click the JSON file --> click raw --> copy all of the text --> go back to codesandbox --> file --> preferences --> CodeSandbox settings --> paste the text in the available box --> refresh the page --> go to the theme area --> find "Custom Theme"

  2. Font size

    File --> preferences --> settings --> type font --> change the font size to fit you!

  3. Automatic Formatter Plugin

    If you mess up your formatting, just save the file (CTR + S or CMD + S) to reformat everything!

  4. Remove semicolons from the end of lines

    File --> preferences --> Codesandbox Settings --> prettier settings --> turn off Semicolons --> go back to main page --> save file

    This should save you some headache dealing with semicolons. In particular, saving me some headaches from explaining whether to use semicolons. :)

We now have the source code on the left and the resulting web page on the right.

When I make a change, the preview shows it immediately.


fork image

Forking is the action of copying a project which allows you to freely experiment and change it without impacting the original project — in a sense, it is like inspecting an element and changing things around!

There are two ways to "fork" a project that isn't yours.

  1. When you get the URL of a sandbox created by other people click the "Fork" button on the top right.
  2. Make changes and then save the file.

There will be a notification on the bottom right stating "Forked Sandbox!", and you are now working on a copy of your own.


Github is an extension of an open-source version control system called Git. Without getting into too many details, Git is an incredibly powerful system that helps solve the problem of having multiple versions of a working project.

github logo

Github is the place where developers store their projects and allow you to use Git in a user-friendly way.

CodeSandbox.io and Github

To save your projects and forks, you will want to create a GitHub account and sign in. There is a sign-in button located on the very top right.

github sign in

This way you’ll be able to save your sandboxes.

You can click a button on the left panel to get a list of sandboxes saved under your account.


Now that you can maneuver around codesandbox, we'll take a look at our code!