How to Create a Custom Middleware in Django?

Middleware is one of Django’s most powerful features. It lets you hook into Django’s request/response cycle and perform actions globally across your project. In this blog post, we’ll explore how to create and use a custom middleware in Django, with practical code examples.

 

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What is Middleware in Django?

Middleware is a lightweight plugin that processes requests and responses globally. It comes between the request and view (or view and response) and can be utilized to:

• Modify the request before it gets to the view.
   
• Modify the response before it gets to the browser.
   
• Handle exceptions globally.
   
• Add headers or logging, etc.
   

 

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Basic Middleware Structure

In Django, a middleware is just a class that defines one or more of the following methods:
 

 

“Let’s build one step by step”

 

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Example: Custom Middleware to Log Request Time

Goal

We want to log the time spent processing every request using a custom middleware.

 

Step 1: Create the Middleware File

Inside your Django app, create a file named middleware.py (if it doesn’t already exist):

 

Step 2: Add Middleware Code

 

Step 3: Add It to settings.py

Open your settings.py file and add your custom middleware to the MIDDLEWARE list:

 

Make sure you place it after SecurityMiddleware but before the view-related ones if needed.

 

Step 4: Test It

Run your Django server:

 

Now visit any URL in your app. You should see logs like this in your terminal:

 

 

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Custom Use Case Ideas

You can modify this middleware for different use cases:

• Block IPs or log IP addresses
   
• Add custom headers
   
• Modify response body (e.g., wrap HTML)
   
• Log user agents or referrers
   
• Automatically compress large responses
   

 

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Tips & Best Practices

• Keep middleware lightweight and fast—don’t do heavy lifting here.
   
• Use middleware for global tasks, not per-view logic.
   
• Log or modify data that doesn't need view-specific context.
   

 

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Bonus: Middleware with Exception Handling

Want to catch and log exceptions? Add this method to your middleware:

 

 

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Conclusion

Middleware gives you powerful control over your Django app’s request-response flow. With a custom middleware, you can log information, transform requests/responses, and catch exceptions at the global level.

Now that you’ve built one yourself, try exploring advanced ideas like authentication checks, rate limiting, or response formatting through middleware!