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Set up freeCodeCamp locally

Follow these guidelines for getting freeCodeCamp locally on your system. This is highly recommended if you want to contribute regularly.

Some of the contribution workflows, like previewing pages for the guide or the coding challenges, debugging and fixing bugs in codebase, requires you to have freeCodeCamp running locally.

Fork the repository on GitHub

'Forking' is a step where you get your own copy of freeCodeCamp's main repository (a.k.a repo) on GitHub.

This is essential as it allows you to work on your own copy of freeCodeCamp on GitHub, or to download (clone) your repository to work on locally. Later, you will be able to request changes to be pulled into the main repository from your fork via a pull request.

ProTip: The main repository at is often referred to as the upstream repository. Your fork at is often referred to as the origin repository.

Follow these steps to fork the repository:

  1. Go to the freeCodeCamp repository on GitHub:
  2. Click the "Fork" Button in the upper right hand corner of the interface (More Details Here)
  3. After the repository has been forked, you will be taken to your copy of the freeCodeCamp repository at

GIF - How to fork freeCodeCamp on GitHub

Preparing the development environment

Once you have the prerequisites installed, you need to prepare your development environment. This is common for many development workflows, and you will only need to do this once.

Follow these steps to get your development environment ready:

  1. Install Git or your favorite Git client, if you haven't already. Update to the latest version; the version that came bundled with your OS may be outdated.

  2. (Optional but recommended) Setup an SSH Key for GitHub.

  3. Install a code editor of your choice.

    We highly recommend using VS Code or Atom. These are great free and open source code editors.

  4. Setup linting for your code editor.

    You should have ESLint running in your editor, and it will highlight anything doesn't conform to freeCodeCamp's JavaScript Style Guide.

    Please do not ignore any linting errors. They are meant to help you and to ensure a clean and simple code base.

Clone your copy of freeCodeCamp

'Cloning' is where you download a copy of a repository from a remote location that is either owned by you or by someone else. In your case, this remote location is your fork of freeCodeCamp's repository that should be available at

Run these commands on your local machine:

  1. Open a Terminal / Command Prompt / Shell in your projects directory

    i.e.: /yourprojectsdirectory/

  2. Clone your fork of freeCodeCamp, replacing YOUR_USER_NAME with your GitHub Username

    git clone --depth=1

This will download the entire freeCodeCamp repository to your projects directory.

Note: --depth=1 creates a shallow clone of your fork, with only the most recent history/commit.

Setup an upstream to the main repository

Now that you have downloaded a copy of your fork, you will need to setup an upstream.

As mentioned earlier, the main repository at is often referred to as the upstream repository. Your fork at is often referred to as the origin repository.

You need a reference from your local clone to the upstream repository in addition to the origin repository. This is so that you can sync changes from the main repository without the requirement of forking and cloning repeatedly.

  1. Change directory to the new freeCodeCamp directory:

    cd freeCodeCamp
  2. Add a remote reference to the main freeCodeCamp repository:

    git remote add upstream
  3. Ensure the configuration looks correct:

    git remote -v

    The output should look something like below:

    origin (fetch)
    origin (push)
    upstream (fetch)
    upstream (push)

Running freeCodeCamp locally on your machine

Now that you have a local copy of freeCodeCamp, you can follow these instructions to run it locally. This will allow you to:

  • Preview edits to pages as they would appear on the learning platform.
  • Work on UI related issues and enhancements.
  • Debug and fix issues with the application servers and client apps.

You can skip running freeCodeCamp locally if you are simply editing files, performing a rebase or resolving merge conflicts. You can always return to this part of the instructions later.

Skip running freeCodeCamp locally

There are currently two methods to run freeCodeCamp locally:

  • Docker (recommended)
  • Local

You are required to follow any one of the above methods.

The Docker setup will ideally result in fewer errors during the installation process and aims to have the best developer experience. We use Docker to install and run the additional software dependencies behind the scenes. This should make it hassle-free and consistent experience across most device/OS types.

If you are having issues using one method, try using the other. If you do run into issues with either method, first perform a web search for your issue and see if it has already been answered. If you cannot find a solution, please search our GitHub issues page for a solution and report the issue if it has not yet been reported.

And as always, feel free to hop on to our Contributors Chat room, for quick queries.

Installing prerequisites

Start by installing the prerequisite software:

Software required for both Docker and Local builds:

Prerequisite Version Notes
Node.js 10.x LTS Schedule
npm (comes bundled with Node) 6.x Does not have LTS releases, we use the version bundled with Node LTS

Docker Build additional prerequisite:

Prerequisite Version Notes
Docker CE Stable -
Docker Compose Stable Must be installed separately if not using macOS or Windows

Local Build additional prerequisite:

Prerequisite Version Notes
MongoDB Community Server 3.6 Release Notes, Note: We are currently on 3.6, an upgrade is planned.


We highly recommend updating to the latest stable releases of the software listed above, also known as Long Term Support (LTS) releases. If Node.js is already installed on your machine, run the following commands to validate the versions:

node -v
npm -v

If you have a different version, please install the recommended version. We can only support installation issues for recommended versions.

Windows users:

Make sure the command line tool you use (e.g., cmd, PowerShell, Git Bash for Windows, WSL) has the correct user privileges. If possible, you should launch the tool with Administrator's privilege. On Windows you should be able to launch as administrator by right-clicking the application and selecting Launch as an Administrator.

I am having issues with installing the recommended prerequisites. What should I do?

We regularly develop on the latest or most popular operating systems like macOS 10.12 or later, Ubuntu 16.04 or later and Windows 10. It is recommended to research your specific issue on resources such as Google, Stack Overflow and Stack Exchange. There is a good chance that someone has faced the same issue and there is already an answer to your specific query.

If you are on a different OS and/or are still running into issues, reach out to the contributors community on our public forum or the contributor's chat room.

Please avoid creating GitHub issues for prerequisite issues. They are out of the scope of this project.

Configuring dependencies

Step 1: Setup the environment variable file

The default API keys and environment variables are stored in the file sample.env. This file needs to be copied to a new file named .env that is accessed dynamically during the installation step.

# Create a copy of the "sample.env" and name it ".env".
# Populate it with the necessary API keys and secrets:

# macOS / Linux
cp sample.env .env

# Windows
copy sample.env .env

The keys in the .env file are not required to be changed to run the app locally. You can leave the default values copied over from sample.env as-is.

Keep in mind if you want to use additional services, you'll have to acquire your own API keys for those services and edit the entries accordingly in the .env file.

Docker Build: If using the Docker build and the Docker installation instructed you to use Docker Toolbox (applies to older versions of macOS and Windows), you need to change DOCKER_HOST_LOCATION in your .env file var to the output from the docker-machine ip command. If you use any Docker supported flavor of Linux or if you use Docker Desktop (new versions of macOS and Windows 10) you can leave DOCKER_HOST_LOCATION to the default value.

Step 2: Install dependencies

This step will install the dependencies required for the application to run:

Docker Build:

npm run docker:init
npm run docker:install
npm run docker:seed

Each of the Docker commands above will take some time to complete. You should wait for each command to fully complete before running the next.

You will also need to install a few npm packages outside of Docker. You can skip this step if you are only running the app locally and will not use git.

npm ci --ignore-scripts

All of the above needs to be run only the first time you set up the local dev environment.

Local Build:

# Install NPM dependencies
npm ci

Step 3: Start MongoDB and seed the database (Local build only)

This step applies to the Local build only; if you are using the Docker build please skip to Step 4.

Unless you have MongoDB running in a setup different than the default, the URL stored as the MONGOHQ_URL value in the .env file should work fine. If you are using a custom configuration, modify this value as needed.

Before you can run the application locally, you will need to start the MongoDB service:

Start the MongoDB server in a separate terminal:

  • On macOS & Ubuntu:

  • On Windows, you must specify the full path to the mongod binary

    "C:\Program Files\MongoDB\Server\3.6\bin\mongod"

    Make sure to replace 3.6 with the version you have installed

ProTip: You can avoid having to start MongoDB every time by installing it as a background service. You can learn more about it in their documentation for your OS

Next, let's seed the database. In this step, we run the below command that fills the MongoDB server with some initial data sets that are required by services. This include a few schemas, among other things.

npm run seed

Step 4: Start the freeCodeCamp client application and API server

You can now start up the API server and the client applications.

Docker Build:

npm run docker:develop

Local Build:

npm run develop

This single command will fire up all the services, including the API server and the client applications available for you to work on.

Once ready, open a web browser and visit http://localhost:8000. If the app loads, congratulations – you're all set!

ProTip: The API Server serves APIs at http://localhost:3000 The Gatsby app serves the client application at http://localhost:8000

If you visit http://localhost:3000/explorer you should see the available APIs.

Congratulations 🎉🎉🎉! You now have a copy of freeCodeCamp's entire learning platform running on your local machine.

How to Sign in when working locally

Your local setup automatically populates a local user in the database. Clicking the Sign In button will automatically authenticate you into the local application.

However, accessing the user portfolio page is a little tricky. In development, Gatsby takes over serving the client side pages and hence you will get a 404 page for the user portfolio when working locally.

Simply clicking the Preview Custom 404 Page button will forward you to the correct page.

Image - How to sign in when working locally

Quick commands reference when working locally

Here is a quick reference to a list of commands that you may occasionally need locally.

Making changes to your clone of freeCodeCamp locally

You can now make changes to files and commit your changes to your local clone of your fork.

Follow these steps:

  1. Validate that you are on the master branch

    git status

    You should get an output like this:

    On branch master
    Your branch is up-to-date with 'origin/master'.
    nothing to commit, working directory clean

    If you are not on master or your working directory is not clean, resolve any outstanding files/commits and checkout master:

    git checkout master
  2. Sync the latest changes from the freeCodeCamp upstream master branch to your local master branch

    Note: If you have any outstanding Pull Request that you made from the master branch of your fork, you will lose them at the end of this step. You should ensure your pull request is merged by a moderator prior to performing this step. To avoid this scenario, you should always work on a branch separate from master.

    This step will sync the latest changes from the main repository of freeCodeCamp. It is important that you rebase your branch on top of the latest upstream/master as often as possible to avoid conflicts later.

    Update your local copy of the freeCodeCamp upstream repository:

    git fetch upstream

    Hard reset your master branch with the freeCodeCamp master:

    git reset --hard upstream/master

    Push your master branch to your origin to have a clean history on your fork on GitHub:

    git push origin master --force

    You can validate your current master matches the upstream/master by performing a diff:

    git diff upstream/master

    The resulting output should be empty.

  3. Create a fresh new branch

    Working on a separate branch for each individual issue helps you keep your local work copy clean. You should never work on the master. This will soil your copy of freeCodeCamp and you may have to start over with a fresh clone or fork.

    Check that you are on master as explained previously, and branch off from there:

    git checkout -b fix/update-guide-for-xyz

    Your branch name should start with a fix/, feat/, docs/, etc. Avoid using issue numbers in branches. Keep them short, meaningful and unique.

    Some examples of good branch names are:

  4. Edit pages and work on code in your favorite text editor

  5. Once you are happy with the changes you should optionally run freeCodeCamp locally to preview the changes

  6. Make sure you fix any errors, and check the formatting of your changes. We have style guides in the docs section for the Guide articles and Coding challenges

  7. Check and confirm the files you are updating

    git status

    This should show a list of unstaged files that you have edited.

    On branch feat/documentation
    Your branch is up to date with 'upstream/feat/documentation'.
    Changes not staged for commit:
    (use "git add/rm <file>..." to update what will be committed)
    (use "git checkout -- <file>..." to discard changes in working directory)
        modified:   docs/
        modified:   docs/
        modified:   docs/
  8. Stage the changes and make a commit

    In this step you should only mark files that you have edited or added yourself. You can perform a reset and resolve files that you did not intend to change, if needed.

    git add path/to/my/changed/file.ext

    Or, alternatively you can add all the unstaged files to the staging area:

    git add .

    Only the files that were moved to the staging area will be added when you make a commit.

    git status


    On branch feat/documentation
    Your branch is up to date with 'upstream/feat/documentation'.
    Changes to be committed:
    (use "git reset HEAD <file>..." to unstage)
        modified:   docs/
        modified:   docs/
        modified:   docs/

    Now, you can commit your changes with a short message like so:

    git commit -m "fix: my short commit message"

    Some examples:

    fix: update guide article for Java - for loop
    feat: add guide article for alexa skills


    We highly recommend making a conventional commit message. This is a good practice that you will see on some of the popular Open Source repositories. As a developer, this encourages you to follow standard practices.

    Some examples of conventional commit messages are:

    fix: update HTML guide article
    fix: update build scripts for Travis-CI
    feat: add article for JavaScript hoisting
    docs: update contributing guidelines

    Keep these short, not more than 50 characters. You can always add additional information in the description of the commit message.

    This does not take any additional time than an unconventional message like 'update file' or 'add'

    You can learn more about why you should use conventional commits here.

  9. If you realise that you need to edit a file or update the commit message after making a commit you can do so after editing the files with:

    git commit --amend

    This will open up a default text editor like nano or vi where you can edit the commit message title and add/edit description.

  10. Next, you can push your changes to your fork.

    git push origin branch/name-here

Proposing a Pull Request (PR)

After you've committed your changes, check here for how to open a Pull Request.

Getting Help

If you are stuck, and need help, let us know by asking in the 'Contributors' category on our forum or the Contributors chat room on Gitter.

There might be an error in the console of your browser or in Bash / Terminal / Command Line that will help identify the problem. Provide this error message in your problem description so others can more easily identify the issue and help you find a resolution.


If the app launches but you are encountering errors with the UI itself, for example if fonts are not being loaded or if the code editor is not displaying properly, you may try the following troubleshooting steps at least once:

# We use a mono repo and have multiple components (server, client, tools, plugins, etc.)
# Use this command to clean up all dependencies in all of the components
npm run clean

# Reinstall npm packages
npm install

# Bootstrap the project
npm run bootstrap

# Seed the database
npm run seed

# Restart the application
npm run develop

If you can't sign in, and instead, you see a banner with an error message saying that it'll be reported to freeCodeCamp, please double-check that your local port 3000 is not in use by a different program.

You can’t perform that action at this time.