JupyterLab/Jupyter Notebook Basics

Starting JupyterLab

Launching JupyterLab is easy, just run jupyter lab in Command Prompt.

A new browser window will be opened and go to http://localhost:8888/lab where we met JupyterLab interface. If it doesn’t open automatically, copy the address from the Command Prompt and open it manually.

JupyterLab opened in Firefox browser

Remember not to close the Command Prompt window as it runs the server process that powers JupyterLab (at port 8888).

Close JupyterLab

Close JupyterLab means close its server process that powers its capabilities.

You can easily close JupyterLab by pressing Ctrl + C twice in the Command Prompt where it is running.

The browser user interface would then show a “disconnected” message.

User Interface in Firefox showing disconnected message


  • Jupyter Notebook document is a file on your system that has .ipynb extension.
  • Jupyter Notebook/JupyterLab server renders that file into a nice web page in the browser (at port 8888 in the example below).
  • The code in the document will be ran by Jupyter Notebook/JupyterLab server, then output the results back to the user interface.
Author: Thijmen I’m currently a SysAdmin located in the Netherlands. Every day I try to keep around a hundred users happy with their network connections and overall, tech-related issues. I also spend my spare time fiddling with web-based applications.

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