Can Python Replace JavaScript?

By James L.

If you have just learned Python and want to leverage your Python knowledge for everything, from machine learning to web development, and wondering whether it can replace JavaScript or not, then you are not alone.

Many years ago I was faced with the same dilemma. At the time I didn’t want to learn JavaScript because I didn’t want to go through the hassle of learning a new programming language again.

So in this article, I have explained whether Python can replace JavaScript or not.

Python cannot replace JavaScript on the client-side because all modern browsers have a built-in JavaScript engine to execute JavaScript code natively on the user’s device while they don’t support Python code. As for the backend, you can choose any of the two languages based on your need or personal preference.

In order for you to fully understand why Python cannot replace JavaScript. First, you need to understand where and how both languages are used.

Python vs JavaScript for Front-end Development

The front-end is the part of a website that user either sees or interacts with directly when they visit a website. It includes everything i.e. images, tables, text, buttons, etc.

Now let’s take a look at how the front-end of a website works. When you access a website, your web browser (chrome, safari, edge, firefox, etc) makes a request to the server and the server responds by sending HTML, CSS, and JavaScript files to your device.

Now the really cool thing about your browser is that it knows how to render these file types depending upon the file type. This is because your browsers have a built-in rendering engine to render HTML, CSS, and JavaScript files.

Your browser’s rendering engine needs to have a JavaScript engine to execute JavaScript code. Fortunately, all modern web browsers are equipped with a JavaScript engine to execute JavaScript code natively on the client’s device. This is not the case for other programming languages including Python. Because of this, JavaScript can easily interact with HTML through the DOM (Document Object Model).

If you are not familiar with DOM, then it is basically an interface that treats an HTML document as a tree-like structure wherein each node is an object representing a part of a document. This means all the parts of a web page are linked together in a tree-like structure so that they can be easily referenced and altered using a scripting language like JavaScript.

Python doesn’t have an easy way to interact with DOM like JavaScript. It is still possible to interact with DOM using Python, but it requires a lot more effort. You will need to use a library like Brython.

Brython takes in Python code and converts it to equivalent JavaScript code. Now, can it replace JavaScript? No, I don’t think so because ultimately the implementation is still going to be in JavaScript.

For the Python code to run natively on the browser, developers of all the web browsers need to add a Python interpreter to their browsers. It will create increased security and vulnerability risks due to the need to provide security updates and support for different interpreters. It will also be resource-heavy for the user’s device due to the added code in the browser. One of the main drawbacks of using Python in the browser is a loss of performance compared to JavaScript.

JavaScript already has a huge ecosystem. Very powerful and robust front-end frameworks like React and Vue.js, used for building dynamic interfaces or UI Components and single-page applications are written in JavaScript.

To have Python replace JavaScript, you would need a good replacement option for Python. But then again, for someone to write a framework or a library for Python, it already needs some traction. JavaScript already has a tremendous first movers advantage.

So for front-end development, Python doesn’t stand a chance against JavaScript, at least in its current state.

Python vs JavaScript for Backend Development

The backend is the server-side of the website. It is responsible for the behind-the-scenes activities of a website. It can be an account login or liking your friend’s Instagram post.

If you want to use Python for backend development then you will end up using Django or Flask framework. Here we will look at Django for comparison because it is the more popular of the two.

If you want to use JavaScript for backend development, then you will end up using Node.js which is a JavaScript runtime environment that helps us to execute JavaScript code as a backend programming language.

The idea of using the same programming language for both front-end and back-end development is every programmer’s dream come true. Due to this reason, JavaScript and Node.js are gaining huge popularity among programmers.

If you are confused about whether to learn Django or Node.js for backend development. Then my advice would be, if you are familiar with Python then you should go ahead and learn Django. Same for JavaScript, if you are familiar with JavaScript then you should learn Node.js.

One thing to remember is if you want to become a full-stack web developer then there is no escaping JavaScript no matter which technologies you choose for backend development.

Below we will compare Django and Node.js under certain criteria to make it easier for you to decide which technology to learn or use.

Django vs Node.js Performance

Django is great at handling CPU-intensive operations whereas Node.js excels at handling multiple concurrent requests, asynchronous I/O-based operations, non-blocking, and event-driven tasks.

Node.js is poor at processing huge amounts of data because of its single-threaded nature.

So, if you need to do lots of CPU-intensive operations like complex mathematical calculations, process huge amounts of data, then Django is a better solution

If you need to handle multiple concurrent requests like in a chat app, then Node.js is a better option.

Django vs Node.js Scalability

Django and Node.js both have great scalability. Big companies like YouTube, Instagram, Spotify, Pinterest, Quora use Django. Same for Node.js, companies like PayPal, LinkedIn, Netflix, Uber, eBay use Node.js. This proves that you can build and maintain highly scalable apps with both technologies.

Django vs Node.js Security

Django is more secure than Node.js. It comes with lots of security features out of the box like Cross-site scripting (XSS) protection, Cross-site request forgery (CSRF) protection, SQL injection protection, Clickjacking protection, SSL/HTTP, and Host header validation.

Node.js doesn’t offer default security settings, so developers need to add security measures themselves to ensure your application is secure.

So when it comes to security Django is a clear winner. However, that doesn’t mean Node.js isn’t the safe option.

Django vs Node.js Cost

Django is more cost-effective than Node.js because Django comes with lots of built-in libraries and methods to help you with the necessary tasks. So it takes less time to make an app with Django than with Node.js. Since “Time is Money”, you will save money when you save time for development.

Django vs Node.js Complexity

Django is more complex than Node.js because, in Django, the developer needs to follow a particular specified way of solving problems, thus making it more complicated. Whereas in Node.js, the developer is free to solve the problem as they like, thus making it less complicated.

Django vs Node.js Flexibility

Node.js is more flexible than Django because, in Node.js, the developer has the freedom to play around with their ideas and make an app from scratch the way they want. On the other hand, Django has a very strict way of doing things, so it may force developers to code certain things in a certain way. Thus, making it less flexible compared to Node.js.

Django vs Node.js User Community

Django and Node.js both have good thriving communities. You will find lots of helpful tools and libraries for both. There are lots of online tutorials to help you get started with both technologies. Both have very active communities to help you if you ever get stuck.

Python vs JavaScript for Machine Learning, Artificial Intelligence, and Data Science

Python offers a wide choice of libraries, packages, and built-in functions to deal with data science, artificial intelligence, and machine learning. Popular machine learning libraries like PyTorch, Scikit-learn, Pandas, TensorFlow, Numpy, etc are available for Python.

JavaScript also comes with a huge number of libraries for data science, artificial intelligence, and machine learning. Popular machine learning libraries like TensorFlow.js, BrainJS, ml.js, stdlib, ConvNetJS, Synaptic, etc are available for JavaScript.

TensorFlow.js library makes it easy for us to define, test, and run the machine learning models in web browsers.

Python is the language of choice for most machine learning projects. However, in some cases where you need to use machine learning directly in the browser, JavaScript may be a better option.

Which language will replace JavaScript?

You may be wondering if Python is not going to replace JavaScript then which language will replace JavaScript.

TypeScript has the potential to replace JavaScript. TypeScript is a “superset” of JavaScript compiled to JavaScript. In other words, TypeScript is JavaScript but has many more additional features. Also, all of the JavaScript frameworks support TypeScript with a little bit of tweaking.

Another interesting development going on in the field of front-end development is WebAssembly (Wasm). WebAssembly (Wasm) is a binary instruction format that runs on all modern web browsers. It is designed as a compilation target for programs written in other programming languages such as C++, C#, Rust, and Python. This means applications written in C++, C#, Rust, and Python can be delivered to the end-user in a web browser without any installation and with near-native performance.

However, WebAssembly is not designed to replace JavaScript. It is designed to complement and work alongside JavaScript and bring high-performance applications to web pages. As WebAssembly matures, it has the potential to replace JavaScript.


If you want to work on machine learning, data science, artificial intelligence, and maybe do a little bit of backend web development work, then learning Python is a better option. But if you want to work on the front-end of a website or become a full-stack web developer, then learning JavaScript is a better option.