Resolving npm Installation Error with Non-ASCII Dash Character

Resolving npm Installation Error with Non-ASCII Dash Character

5 April 2024 Stephan Petzl Leave a comment Tech-Help

When installing packages with npm, such as Appium, you might encounter an error message that suggests an issue with a “non-ascii dash.” This typically occurs when the command entered in the terminal has invalid characters. In this guide, we’ll walk you through the steps to resolve this issue and successfully install Appium.

Understanding the Error

The error message you may see is as follows:

npm ERR! arg Argument starts with non-ascii dash, this is probably invalid: [‘-g’, ‘appium’]
npm ERR! Invalid tag name “-g”: Tags may not have any characters that encodeURIComponent encodes.

This error is pointing towards a problem with the dash character preceding the ‘g’ in the install command. It’s a common issue that can arise when a command is copied from a source that doesn’t use plain text format, such as a word processor or a website with special formatting.

How to Fix the Issue

To fix this error, you should avoid copying the command from formatted text and instead type it directly into your command prompt or terminal. Here’s the correct command:

npm install -g appium

Make sure to use the standard hyphen-minus character (ASCII 45) for the dash. This character is typically located on the same key as the underscore (_) on standard keyboards.


If you’re still experiencing issues after entering the command manually, consider the following steps:

  • Ensure that your Node.js and npm versions are up to date.
  • Check your keyboard settings to make sure it’s not substituting characters automatically.
  • Try using a different text editor or terminal to ensure there’s no hidden formatting.
  • Clear your npm cache by running npm cache clean --force and then try installing again.


By typing the installation command directly into your command prompt or terminal and ensuring the correct character usage, you should be able to overcome the npm non-ascii dash error and proceed with the installation of Appium or any other npm package. Remember that attention to detail with command syntax is crucial for successful software installations and configurations.

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