404 page#

Because Sphinx does not create a 404 page by default, you can use the sphinx-notfound-page extension for 404 pages. While originally developed to be used with Read the Docs, this extension can be used in other hosting services. For more information, see the extension’s documentation.

Install the extension#

Install and enable the sphinx-notfound-page extension with:

python -m pip install sphinx-notfound-page

Consider adding this extension to your requirements_doc.txt file.

Add the extension to the conf.py file#

After installing the sphinx-notfound-page extension, add it to your conf.py file:

# Add the extension
extensions = [

Configure your 404 page#

You can use the default 404 page that the ansys-sphinx-theme package supplies or create and use a custom 404 page.

Use the default 404 page#

To use the default 404 page, you can use the generate_404 function in the ansys_sphinx_theme module to create and use a custom cover page:

from ansys_sphinx_theme import generate_404

# Configure sphinx-notfound-page
notfound_context = {
'body': generate_404(<organisation_which_the_project_belongs_to>,

Create and use a custom 404 page#

To create and use a custom 404 page, do the following:

  1. Create a 404.rst file next to the conf.py file.

  2. To suppress the spurious document isn't included in any toctree Sphinx warning, include the :orphan: attribute at the top of this 404.rst file:

    Error 404 Not Found
    The page you are requesting does not exist.
  3. Update the notfound_template variable in the conf.py to the location of your 404.rst file:

    # Configure sphinx-notfound-page
    notfound_template = "path/to/404.rst"