Troubleshooting Guide: Fixing the 'JavaScript Error: IPython is Not Defined' Issue

If you're working with Jupyter Notebooks or any other environment that uses IPython, you may have encountered the "JavaScript Error: IPython is not defined" issue. This error typically occurs when there is a problem with your IPython installation or when your browser can't load the required JavaScript files.

In this guide, we will walk you through the steps to resolve this issue, ensuring that your IPython environment works seamlessly. Let's get started!

Table of Contents

  1. Check Your IPython Installation
  2. Update Jupyter and IPython
  3. Clear Your Browser Cache
  4. Disable Browser Extensions
  5. FAQ

Check Your IPython Installation

The first thing you should do when encountering the "IPython is not defined" error is to check if IPython is installed correctly.

To do this, open a terminal or command prompt and run the following command:

ipython --version

If IPython is installed, you will see the version number. If not, you will need to install IPython using the following command:

pip install ipython

Update Jupyter and IPython

If IPython is installed but you're still experiencing the error, it's possible that you're using an outdated version of Jupyter or IPython. To update both, run the following commands:

pip install --upgrade jupyter
pip install --upgrade ipython

After updating, restart your Jupyter Notebook server and check if the error has been resolved.

Clear Your Browser Cache

Sometimes, the "IPython is not defined" error can be caused by cached data in your browser. To resolve this, clear your browser cache.

Here's how you can do this for some popular browsers:

  • Google Chrome: Click the three-dot menu in the top right corner > More tools > Clear browsing data.
  • Mozilla Firefox: Click the hamburger menu in the top right corner > Options > Privacy & Security > Clear Data.
  • Safari: Click Safari in the menu bar > Preferences > Privacy > Manage Website Data > Remove All.

After clearing the cache, refresh your Jupyter Notebook and check if the error has been resolved.

Disable Browser Extensions

Browser extensions can sometimes interfere with the functionality of Jupyter Notebooks. To rule out this possibility, disable all browser extensions and restart your browser.

If this resolves the issue, you can enable your extensions one by one to identify which one is causing the problem.


1. What is IPython?

IPython is an interactive command-line shell for Python. It provides an enhanced interface and additional features compared to the standard Python shell. IPython is used as the backend for Jupyter Notebooks.

2. What is Jupyter Notebook?

Jupyter Notebook is an open-source web application that allows users to create and share documents containing live code, equations, visualizations, and narrative text. It is widely used for data analysis, machine learning, and scientific research.

3. Can I use Jupyter Notebook without IPython?

Jupyter Notebook relies on IPython as its kernel to execute Python code. While Jupyter supports other languages with different kernels, to use Jupyter Notebook with Python, you need IPython installed.

4. How do I restart my Jupyter Notebook server?

To restart your Jupyter Notebook server, first, close all open notebooks, then go to the terminal or command prompt where you started the server and press Ctrl+C twice to shut it down. Finally, start the server again by running jupyter notebook.

5. How do I update my Python version?

To update your Python version, visit the official Python website and download the latest version for your operating system. Follow the installation instructions provided on the website.

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