Django: Creating a custom 404 Error Page

Introduction

The 404 error is shown when the user tries to navigate to a URL that doesn't exist. By default, Django returns a page when this error is raised. However, we can set a custom page to be displayed in a few steps.

Creating a Django project:

First, we create a Django project with the following command:

$ django-admin startproject myproject

Running the Server

To run the server, we use:

$ python manage.py runserver

We can see the Django welcome page displayed when we visit http://127.0.0.1:8000 This shows the server is up and running.

The Default Not Found Page

Let's go to a page that doesn't exist, like http://127.0.0.1:8000/randompage. We can see that Django returns this page:

However, this page is only shown because DEBUG is set to True. Let's see what happens when we change that in the settings.py file.

DEBUG = False
ALLOWED_HOSTS = ['127.0.0.1']

Note: When we set DEBUG to False, we have to define the allowed hosts.

Now, when we visit http://127.0.0.1:8000/randompage we see a different page:

As we can see, this page is quite boring so let's add our own page.

Customizing the Not Found Page

Create a views.py file in the project directory.

Now, the project directory should look like this:

├── db.sqlite3
├── manage.py
└── myproject
    ├── __pycache__
    ├── __init__.py
    ├── asgi.py
    ├── settings.py
    ├── urls.py
    ├── views.py
    └── wsgi.py

Defining a view to render the page:

from django.shortcuts import render


def error_view(request, exception):
    return render(request, '404.html', status=404)

Adding the handler for the error:

Our custom handler404 will override the Page Not Found view. So, we edit our urls.py file to look like this:

from django.contrib import admin
from django.urls import path
urlpatterns = [
    path('admin/', admin.site.urls),
]
handler404 = "myproject.views.error_view"

Adding the template:

Create a folder named templates in the project directory. Add your custom page that is to be displayed to this folder. Now, the project directory should look like this:

├── db.sqlite3
├── manage.py
├── templates
    ├── 404.html
└── myproject
    ├── __pycache__
    ├── __init__.py
    ├── asgi.py
    ├── settings.py
    ├── urls.py
    ├── views.py
    └── wsgi.py

Updating the template directory in the settings.py file.

We add os.path.join(BASE_DIR,'templates') to the DIRS to allow Django to find our template. Now, the settings.py file should look like this:

TEMPLATES = [
    {
        ...
        'DIRS': [os.path.join(BASE_DIR,'templates')],
        ...
    },
]

Final View:

When we refresh the http://127.0.0.1:8000/randompage. We can see our custom page is displayed like this:

Conclusion

Now our custom 404 Page Not Found page is visible for any non-existing page on the website. I hope you enjoyed this tutorial, your feedback is more than welcome!