Ever wondered how to add a captcha field in your Django forms? I’ll show you how to do this! Captchas are a great way to secure your site from spamming, or bot attacks. So, adding a captcha field to your authentication forms are a great way to enhance your site’s UX. Let’s get started.

Make a Captcha Field in Django

Project Setup

For this, you need to install a package called django-simple-captcha. This enables us to easily us captcha field in our Django forms just like other fields.

pip install django-simple-captcha

Now, create a django project and a django app:

django-admin startproject django_captcha
cd django_captcha
django-admin startapp app

Modifying settings.py

Add ‘app‘ (Your app name) and 'captcha‘ (app provided by django-simple-captcha) in your INSTALLED_APPS of settings.py:

....
INSTALLED_APPS = [ 
'django.contrib.admin',
'django.contrib.auth', 
'django.contrib.contenttypes',
'django.contrib.sessions', 
'django.contrib.messages',
'django.contrib.staticfiles', 
'app', 
'captcha']
....

Configuring root urls

Modify the django_captcha/urls.py as below:

from django.contrib import admin
from django.urls import path, include
urlpatterns = [
    path('admin/', admin.site.urls),
    path('', include('app.urls')),
    path('captcha/', include('captcha.urls'))
]

We’re routing the empty path to our app. And we’re making our project accessible to captcha package by adding ‘captcha’ in our root urls.

I’ll be making a templates folder in our app itself, so I won’t bother about tweaking the settings.py for template lookup.

Configuring app/urls

Add the following lines to app/urls.py:

from django.urls import path
from . import views
urlpatterns = [
    path('', views.home, name="home")
]

Creating a captcha in forms.py

Now, I’ll create a django form in app/forms.py (Make a file called forms.py in your app folder). Add the following lines to it:

from django import forms
from captcha.fields import CaptchaField
class MyForm(forms.Form):
    # You can add other form fields here!
    captcha = CaptchaField()

For the sake of simplicity, I’m adding only the captcha field, but feel free to add whatever you want.

Making our views

I’ll use the django messages framework displaying success and failure of the captcha (This is optional, can do this without this). Make sure your app/views.py looks like this:

from .forms import MyForm
from django.shortcuts import render
from django.contrib import messages
def home(request):
    if request.method == "POST":
        form = MyForm(request.POST)
        if form.is_valid():
            messages.success(request, 'Success!')
        else:
            messages.error(request, 'Wrong Captcha!')
    form = MyForm()
    return render(request, 'home.html', {'form': form})

As you can see, I’m just doing basic form manipulation in my views (a captcha field is just a form field right?). Now, finally we need to make our template called ‘home.html‘. Make a file called ‘home.html’ in app/templates/home.html (Yeah, create a folder with name templates too).

Making our template

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Captcha</title>
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css"
        integrity="sha384-B0vP5xmATw1+K9KRQjQERJvTumQW0nPEzvF6L/Z6nronJ3oUOFUFpCjEUQouq2+l" crossorigin="anonymous">
</head>
<body>
    <h3 class="text-center mt-3 text-info">Django Captcha</h3>
    {% if messages %}
    {% for message in messages %}
    <div class="alert text-center mt-5 alert-{{message.tags}}">
        {{message}}
    </div>
    {% endfor %}
    {% endif %}

    <form action="" method="post" class="text-center mt-5" novalidate>
        {% csrf_token %}
        {{form.captcha}}
        <input type="submit" class="btn btn-primary" value="Submit">
    </form>
</body>
</html>

I’m using bootstrap in my template. Just place bootstrap cdn in your <head> … </head> for your template.

Yeah, we’re done with this. Finally you just need to do these steps,

python manag.py makemigrations
python manage.py migrate

Now, start your development server with python manage.py runserver and open 127.0.0.1:8000 in your favourite browser. That’s it!

Check out my code at GitHub https://github.com/Chandu-4444/django-captcha