Fixing the TypeScript Command 'tsc' Not Running in Terminal and PowerShell

The Code Points March 23, 2025 0

If you’re a TypeScript developer, you might encounter a frustrating issue where the TypeScript compiler (tsc) command doesn’t work in Terminal or PowerShell. This can halt your development process, but don’t worry! In this guide, we will walk you through several troubleshooting steps to resolve the issue of the TypeScript command 'tsc' not running.

Why Does 'tsc' Not Work in Terminal or PowerShell?

There are a few reasons why the tsc command may not run in Terminal or PowerShell. The most common causes include:

1. TypeScript is not installed: TypeScript may not be installed globally or locally.
2. Path issue: The TypeScript binaries may not be in your system’s PATH environment variable.
3. Corrupted installation: Sometimes, TypeScript installation may be corrupted, causing issues with the tsc command.

Let’s explore how you can fix these issues and get the tsc command working again.

Step 1: Verify TypeScript Installation

Before troubleshooting further, make sure that TypeScript is installed. To verify this, open your Terminal or PowerShell and type:

tsc --version

If you see something like tsc: command not found or the command does not return a version number, TypeScript is either not installed or not set up correctly.

Step 2: Install TypeScript Globally

If TypeScript is not installed, or if you suspect it's not installed globally, you can install it using npm (Node Package Manager). To install TypeScript globally, run:

npm install -g typescript

The -g flag ensures TypeScript is installed globally, meaning the tsc command will be available from anywhere on your system.

Once the installation is complete, verify the installation by checking the version again:

tsc --version

This should return the installed version of TypeScript.

Step 3: Check Your PATH Environment Variable

If TypeScript is installed but the tsc command still doesn’t work, the issue could be related to your PATH environment variable. The PATH variable is responsible for telling the system where to look for executable files. If TypeScript was installed globally, its binaries should be located in a directory that’s included in your PATH.

For Windows (PowerShell or Command Prompt)

1. Open the Start menu, search for "Environment Variables", and select Edit the system environment variables.
2. Click the Environment Variables button.
3. In the System Variables section, find the Path variable and click Edit.
4. Make sure that the following path is included:

C:\Users\<YourUsername>\AppData\Roaming\npm

This is where npm installs global packages by default.

If it's not there, add it and click OK to save.

For macOS/Linux

Open your terminal and check the contents of your .bash_profile or .zshrc (depending on your shell):

nano ~/.bash_profile

Or for Zsh users:

nano ~/.zshrc

Look for any references to npm directories. You should have a line similar to:

export PATH="$PATH:$(npm bin -g)"

If the path is not present, add it, then save and close the file.

Reload the terminal session with:

source ~/.bash_profile

Or for Zsh users:

source ~/.zshrc

Step 4: Restart Terminal or PowerShell

After updating your PATH variable, restart your terminal or PowerShell window to ensure the new configuration takes effect. You can do this by simply closing and reopening the terminal.

Step 5: Check for Conflicting Installations

If you’re still having trouble, there might be a conflict with other versions of TypeScript installed locally in a project directory or through other package managers like Yarn.

Check for any local installations by running:

npm list -g typescript

This will show you the version of TypeScript installed globally. If a local version is installed in a project, it might be conflicting with the global installation.

To remove a local TypeScript installation, navigate to the project folder and run:

npm uninstall typescript

After uninstalling any local installations, run the global installation again:

npm install -g typescript

Step 6: Reinstall Node.js and npm

If all else fails and the tsc command still doesn’t work, it might be a sign that your Node.js or npm installation is corrupted. In this case, reinstalling Node.js will also reinstall npm, which will ensure everything is set up properly.

Download and install the latest version of Node.js from the official website: https://nodejs.org.
After installation, run the following commands to verify that Node.js and npm are correctly installed:

node --version
npm --version

Reinstall TypeScript globally:

npm install -g typescript

Step 7: Verify tsc Command

After following all the above steps, check again if the tsc command is working by running:

tsc --version

If everything was set up correctly, you should see the installed version of TypeScript.

Conclusion

The issue of the TypeScript command tsc not running in Terminal or PowerShell is often due to either an incorrect installation or problems with your system’s PATH configuration. By following the steps outlined above—such as verifying the installation, adjusting your PATH, and reinstalling Node.js—you can quickly resolve this issue and continue your development work without further interruption.

If you're still experiencing problems, double-check your system configuration or consider reaching out to TypeScript or Node.js community forums for further troubleshooting.