How to Add Tags to Cells in Jupyter Notebook

Jupyter Notebook is one of the most widely used tools in data science, machine learning, and research notebooks. It allows users to create and share documents that contain live code, equations, visualizations, and narrative text. As projects grow in complexity, the need to organize your notebook beyond the default structure becomes essential. That’s where cell tags come in handy.

TLDR

Tags in Jupyter Notebook help you organize and manage cells for use with tools like nbconvert, custom exporters, and grading systems. To add tags, you must enable the Cell Toolbar via the View menu, select “Tags”, and then enter your desired tag names for each cell. These tags can be used to filter or customize how cells are processed, exported, or excluded. This functionality is especially useful for educational workflows and complex documentation tasks.

What Are Tags in Jupyter Notebook?

Tags are user-defined keywords or labels that can be added to notebook cells. They don’t affect the execution of the code directly but provide metadata that external tools can interpret for various purposes.

Some of the common uses of tags include:

• Excluding code or content from PDF/HTML exports
• Highlighting certain cells for review or revision
• Setting up assignments and auto-graded quizzes using tools like nbgrader
• Organizing cells by functionality or topic

Why Use Tags?

When you’re working with long or complex notebooks, tags can make it easier to:

• Identify which cells belong to a particular section
• Hide or reveal information for different audiences (e.g., students vs instructors)
• Exclude setup or test cells before publishing

They are particularly useful for educators, data scientists, and developers who need fine-grained control over how the contents of a notebook are interpreted by downstream systems.

Getting Started: How to Enable the Tag Interface

By default, the Jupyter Notebook interface doesn’t show the tag editor. You need to manually enable it from the notebook UI. Here’s how you do it:

1. Open your Jupyter Notebook (.ipynb file).
2. Go to the top menu and click on View.
3. Select Cell Toolbar from the dropdown.
4. From the expanded menu, choose Tags.

This will bring up a tag editor to the right side of every cell. You can now add and manage tags for each individual cell.

How to Add Tags to a Cell

Once the tag toolbar is enabled, adding tags becomes straightforward:

1. Click the cell to which you want to add a tag.
2. Look to the right-hand side of the cell and find the small field labeled Add Tag.
3. Enter the name of the tag (e.g., hide_input, solution, grade).
4. Press Enter to confirm.

You can add multiple tags by pressing Enter after each one. The tags will appear as clickable labels next to the cell.

Common Tags and Their Use Cases

Here are some tags frequently used in conjunction with tools and workflows that extend Jupyter functionality:

• hide_input: Hides the input code block in rendered exports (e.g., PDFs).
• remove_cell: Completely removes the cell during export.
• solution: Marks the cell as a solution in an nbgrader assignment.
• grade: Indicates the cell should be auto-graded by nbgrader.
• parameters: Used in Papermill for parameterizing notebooks.

Tags work as metadata, which downstream tools interpret to take specific actions. Their usefulness depends on the ecosystem or extension you are utilizing.

Managing Tags Efficiently

If you are working with many tags across multiple cells, it can become difficult to track everything. Here are a few suggestions:

• Be consistent: Use consistent naming conventions. Avoid typos and overly long tag names.
• Document your tags: Include a markdown cell that describes what each tag is for.
• Use extensions: Consider using Jupyter Notebook extensions (like nbextensions) that provide enhanced tag handling and visualization.

Advanced Use: Tags with nbconvert

The nbconvert tool allows conversion of notebooks into HTML, PDF, LaTeX, and more. Tags can be used to control the visibility of cells during export. For example, with the hide_input tag, you can suppress the input code cells from showing in the final document.

To make use of tags during export, run the following command:

jupyter nbconvert mynotebook.ipynb --to html --TagRemovePreprocessor.enabled=True --TagRemovePreprocessor.remove_input_tags='{"hide_input"}'

This command tells nbconvert to hide all input cells that are tagged as hide_input.

Using Tags with nbgrader

For academic purposes, tags are valuable in the nbgrader workflow. This tool allows educators to create assignments, automatically grade them, and return feedback. Tags are central to marking which cells contain solutions, student inputs, or auto-graded tasks.

Common tags in nbgrader include:

• grade: Marks the cell to be automatically graded.
• solution: Indicates where the student should input their answer.
• locked: Prevents editing of the cell by students.

The tags trigger how nbgrader processes the notebook, ensuring fairness and reproducibility in grading.

Best Practices for Using Tags

To make the most of the tagging system in Jupyter, here are some recommended practices:

• Plan ahead: Think about what you want to achieve with tags before you begin tagging cells.
• Stay organized: Use a small, consistent set of tags relevant to your workflow.
• Avoid clutter: Don’t overload cells with too many tags—it can make your notebook messy.
• Use markdown cells to explain your tagging system for collaborators or students.

Limitations of Tags

As useful as tags are, they have a few limitations you should be aware of:

• Tags are only meaningful when used with compatible tools (e.g., nbgrader, nbconvert, Paperspace, etc.).
• There is no validation—misspelled tags will not throw errors but may not behave as expected.
• Tag management becomes less efficient in very large notebooks unless supported by extensions.

Troubleshooting Common Issues

If you run into problems while working with tags, consider the following checks:

• Tags not visible? Make sure the tag toolbar is enabled in the View → Cell Toolbar → Tags menu.
• Tags not working during export? Double-check the correct flags were passed to nbconvert, and ensure that the tags match exactly.
• Conflicts between tools? Some Jupyter extensions or exporters may interpret tags differently—consult the documentation for each plugin or exporter.

Conclusion

Tags in Jupyter Notebook are a powerful way to enhance your workflow, whether you’re grading assignments, preparing public reports, or managing complex projects. While it may take a small amount of initial effort, proper use of tags can save time and bring clarity to your notebooks. With consistent usage and smart integration with tools like nbconvert or nbgrader, tags help transform Jupyter from a simple notebook into a fully customizable and automated document pipeline.