Jupyter Notebook opens through your command line or a graphical launcher, not by double-clicking a file

Jupyter Notebook is a web-based tool that runs on your computer and opens in your browser. Unlike most programs, you do not launch it by finding an icon on your desktop. Instead, you start it from your command line (Terminal on Mac, Command Prompt on Windows) or through an process launcher. Once running, Jupyter creates a local web server and displays your notebooks in a browser window — usually at an address like localhost:8888.

Before you can open Jupyter, you need to install it. The most common way is through Anaconda, a package manager that bundles Python, Jupyter, and hundreds of data science libraries together. If you have already installed Anaconda, Jupyter is already on your computer. If you installed Python separately, you can add Jupyter using the pip package manager by typing pip install jupyter in your command line.

Key Takeaways

  • Jupyter Notebook starts from your command line by typing jupyter notebook, not from a desktop icon or file menu.
  • Anaconda is the easiest installation route because it includes Jupyter, Python, and common libraries in one read.
  • Once running, Jupyter opens in your default web browser at a local address, and you can create or open notebook files from there.
  • Your notebooks are saved as .ipynb files on your computer, and you can organize them in folders just like any other document.
  • Closing the command line window stops Jupyter, so keep it open while you are working.

Installing Jupyter through Anaconda

Anaconda is the simplest path because it handles all the setup at once. Go to anaconda.com, read the installer for your operating system (Windows, Mac, or Linux), and run it. During installation, accept the default settings unless you have a specific reason to change them. The installer will add Anaconda to your system and create a folder where all your packages live.

Once Anaconda is installed, you do not need to do anything else to get Jupyter. It is already there. You can verify this by opening your command line and typing jupyter --version. If a version number appears, Jupyter is ready to use.

Opening Jupyter from your command line

Open your command line process. On Windows, search for "Command Prompt" or "PowerShell" in your Start menu. On Mac, open Applications, go to Utilities, and click Terminal. On Linux, open your terminal process — the name varies by distribution.

Type the command jupyter notebook and press Enter. Jupyter will start and print several lines of text to your command line. Within a few seconds, your default web browser will open automatically and display the Jupyter home page. If it does not open automatically, look at the command line output for a line that starts with http://localhost:8888. Copy that address and paste it into your browser's address bar.

The Jupyter interface shows a file browser on the left side. You are looking at the contents of the folder where you ran the command. From here, you can create a new notebook, open an existing one, or navigate to a different folder on your computer.

Creating and opening notebooks

To create a new notebook, click the New button in the top right corner of the Jupyter home page. A dropdown menu appears with options including Python 3 (or whichever Python version you have installed). Click it, and a new blank notebook opens in a new browser tab.

A notebook is divided into cells. Each cell is a box where you type either code or text. Click inside a cell, type your code or notes, and press Ctrl+Enter (or Cmd+Enter on Mac) to run it. The output appears directly below the cell. You can add new cells, delete them, rearrange them, and save your work — all from the menu at the top of the notebook.

To open a notebook you have already created, navigate to it in the Jupyter file browser and click its name. Notebooks are saved as .ipynb files, which is Jupyter's native format. You can also save your work as a Python file (.py), a PDF, or HTML from the File menu.

Organizing your notebooks in folders

Jupyter's file browser works like a folder explorer on your computer. When you start Jupyter, it opens in whatever folder you were in when you typed the command. To work in a different location, navigate to that folder in your command line before starting Jupyter, or use the file browser to navigate once Jupyter is open.

Create folders inside Jupyter by clicking the New button and selecting Folder. You can then move notebooks into those folders or create notebooks directly inside them. This is useful if you are working on multiple projects — keep each project's notebooks in its own folder.

Keeping Jupyter running while you work

While you are using Jupyter in your browser, the command line window must stay open. That window is running the server that powers Jupyter. If you close it, Jupyter stops working and your browser will lose connection to it.

You can minimize the command line window so it is out of the way, but do not close it. When you are done working, you can close the browser tab, close the command line window, or both. Closing Jupyter does not delete your notebooks — they are saved on your computer as .ipynb files and will open again the next time you start Jupyter.

Troubleshooting common startup problems

If you type jupyter notebook and get a "command not found" error, Jupyter is not installed or not in your system path. If you used Anaconda, try opening Anaconda Navigator instead — it is a graphical process that came with Anaconda and can launch Jupyter without typing commands. Search for "Anaconda Navigator" in your applications menu, open it, and click the Launch button under Jupyter Notebook.

If Jupyter starts but your browser does not open automatically, copy the http://localhost:8888 address from the command line and paste it into your browser's address bar. If you see a message about the port being in use, another instance of Jupyter is already running. Either close that instance first or let Jupyter use a different port — it will suggest one automatically.

If you installed Python without Anaconda and pip install jupyter did not work, make sure Python and pip are in your system path. On Windows, this usually means reinstalling Python and checking the box that says "Add Python to PATH" during installation.

Frequently Asked Questions

Do I need to install anything besides Jupyter to use it?

You need Python, which Anaconda includes automatically. If you installed Python separately, Jupyter will use that Python installation. You do not need anything else to start — Jupyter comes with basic libraries built in, and you can add more libraries later as you need them.

Can I open Jupyter without using the command line?

Yes. If you installed Anaconda, open Anaconda Navigator from your applications menu and click the Launch button under Jupyter Notebook. This does the same thing as typing the command, just with a graphical interface instead.

What if I want to open a notebook file that is in a different folder?

Navigate to that folder in the Jupyter file browser, or start Jupyter from that folder in your command line. If you are in your command line, type cd followed by the path to the folder, then type jupyter notebook. Jupyter will open showing that folder's contents.

Will closing my browser tab stop Jupyter?

No. Closing the browser tab just closes that window — Jupyter keeps running in the command line. You can open a new browser tab and go back to localhost:8888 to reconnect. Jupyter stops only when you close the command line window or press Ctrl+C in it.

Where are my notebooks saved on my computer?

Notebooks are saved in the folder where you started Jupyter. If you started Jupyter from your Documents folder, your notebooks are in Documents. You can see them in the Jupyter file browser, and you can also find them using your computer's file explorer — they are regular .ipynb files that live on your hard drive like any other document.