How to create 404 view in django

DjangoHow-ToBeginner · 3 min read

How to Create a Custom 404 View in Django

In Django, create a custom 404 view by defining a function that takes request and exception parameters and returns a HttpResponseNotFound with your custom template. Then, set handler404 in your urls.py to point to this view and ensure DEBUG = False in settings.py for it to work.

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Syntax

To create a custom 404 view in Django, define a function with two parameters: request and exception. This function should return a HttpResponseNotFound or use render to display a 404 template. Then assign this function to handler404 in your urls.py.

request: The HTTP request object.
exception: The exception that triggered the 404.
HttpResponseNotFound: A response with HTTP status 404.
handler404: A special variable in urls.py to register the 404 view.

python

from django.http import HttpResponseNotFound
from django.shortcuts import render

def custom_404_view(request, exception):
    return render(request, '404.html', status=404)

# In urls.py
handler404 = 'myapp.views.custom_404_view'

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Example

This example shows a complete custom 404 view that renders a friendly HTML page when a user visits a non-existent URL. It also shows how to configure handler404 in urls.py and the required settings.

python

# views.py
from django.shortcuts import render

def custom_404_view(request, exception):
    return render(request, '404.html', status=404)

# urls.py
from django.urls import path

urlpatterns = [
    path('', lambda request: render(request, 'home.html')),
]

handler404 = 'myapp.views.custom_404_view'

# settings.py
DEBUG = False
ALLOWED_HOSTS = ['localhost', '127.0.0.1']

# 404.html (template)
# <html>
# <head><title>Page Not Found</title></head>
# <body><h1>Oops! Page not found.</h1><p>The page you requested does not exist.</p></body>
# </html>

Output

When visiting a non-existent URL, the browser shows the 404.html page with status code 404 and message "Oops! Page not found."

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Common Pitfalls

Not setting DEBUG = False in settings.py will cause Django to show its default debug 404 page instead of your custom one.
Forgetting to add your domain to ALLOWED_HOSTS can block your custom 404 page from showing.
Not assigning handler404 correctly in urls.py will keep the default 404 behavior.
Using a view without the exception parameter will cause errors.

python

### Wrong: Missing exception parameter
from django.shortcuts import render

def bad_404_view(request):  # Missing 'exception'
    return render(request, '404.html', status=404)

### Right: Include exception parameter
from django.shortcuts import render

def good_404_view(request, exception):
    return render(request, '404.html', status=404)

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Quick Reference

Define a 404 view with request and exception parameters.
Return a response with status 404 using render or HttpResponseNotFound.
Set handler404 in urls.py to your view's path as a string.
Set DEBUG = False and configure ALLOWED_HOSTS in settings.py.

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Key Takeaways

Always define your custom 404 view with both request and exception parameters.

Set handler404 in urls.py to point to your custom 404 view as a string.

Ensure DEBUG is False and ALLOWED_HOSTS is set for the custom 404 page to display.

Use render() with status=404 to return a proper 404 response with a template.

Test your 404 page by visiting a non-existent URL after deployment.