Asynchronous Django: How to Make Your App Faster with async Views

Django has long been known for its synchronous request-response cycle, but with Django 3.1+, support for asynchronous views was introduced, allowing developers to take advantage of Python’s asyncio capabilities. This means faster response times, improved scalability, and better handling of concurrent requests.

In this guide, we’ll explore:
- How Django handles async views
- When to use async views for better performance
- Examples of async views in Django

1. Why Use Asynchronous Views in Django?

Traditionally, Django processes each request synchronously, meaning each request is handled one at a time, blocking the execution of other requests. This can be inefficient, especially when making slow I/O operations like:

• Fetching data from an external API
• Querying the database
• Performing file I/O operations

With asynchronous views, Django can process multiple requests concurrently without blocking the main thread — leading to significant performance gains!

2. Setting Up an Async Django View

Let’s start with a simple async view that simulates a delay using asyncio.sleep() and compare it with a synchronous view.

Synchronous View (Traditional Django View)

import time 
from django.http import JsonResponse 
 
def sync_view(request): 
    time.sleep(3)  # Simulating a slow operation 
    return JsonResponse({"message": "Sync response completed!"})

Problem: This view blocks the request-response cycle for 3 seconds, making the app slow under load.

Asynchronous View (Non-Blocking Response)

import asyncio 
from django.http import JsonResponse 
 
async def async_view(request): 
    await asyncio.sleep(3)  # Simulating a slow operation 
    return JsonResponse({"message": "Async response completed!"})

Benefits of Async Views:

• Uses await to handle non-blocking operations
• Does not block the entire process while waiting
• Handles multiple requests concurrently

3. When to Use Async Views?

While async views can significantly improve I/O-bound operations, they are not always the best solution for CPU-bound tasks. Here’s a simple guide:

Good Use Cases for Async Views:

• Calling an external API
• Handling websocket connections
• Executing long-running database queries
• Processing large file uploads

Avoid Async Views for:

• CPU-heavy tasks like image processing, complex calculations (use Celery instead!)

4. Calling External APIs with Async Django Views

If your Django app interacts with third-party APIs, async views can speed up API calls significantly.

Example: Fetching API Data with httpx

Instead of using requests (which is synchronous), we use httpx, an async HTTP client for Python.

import httpx 
from django.http import JsonResponse 
 
async def fetch_data(request): 
    async with httpx.AsyncClient() as client: 
        response = await client.get("https://jsonplaceholder.typicode.com/todos/1") 
    return JsonResponse(response.json())

Why to use httpx to call an API?

• It supports async API calls
• It prevents blocking the main thread
• It is faster than traditional requests

5. Using Async ORM Queries in Django

As of Django 4.1+, Django ORM supports async database queries using await.

from myapp.models import Product 
from django.http import JsonResponse 
 
async def get_product(request, product_id): 
    product = await Product.objects.aget(id=product_id)  # Async database query 
    return JsonResponse({"name": product.name, "price": product.price})

Benefits of Async ORM Queries:

• It prevents blocking while waiting for the database
• It is useful when handling multiple concurrent DB queries

Note:

• aget() is the async equivalent of get().
• Not all ORM operations are async-compatible yet!

6. Combining Sync and Async Views

Django allows you to mix sync and async views seamlessly. If you call a sync function from an async view, use sync_to_async.

from django.http import JsonResponse 
from asgiref.sync import sync_to_async 
import time 
 
def blocking_task(): 
    time.sleep(3)  # Simulate a slow synchronous task 
    return "Sync task completed" 
 
async def mixed_view(request): 
    result = await sync_to_async(blocking_task)()  # Run blocking code in an async-safe way 
    return JsonResponse({"message": result})

Final Thoughts: Async Views = Faster Django Apps!

By utilizing Django’s async capabilities, you can:
- Improve response times for API-heavy applications
- Handle multiple requests concurrently
- Scale your Django app for high performance

Are you using async views in Django? Let me know your experience! 👇