Behind every chat app is a large stack of intertwined technologies. Near the bottom of that stack is the programming language (or languages) that powers everything else.
So what is the best programming language for chat applications?
Well, there isn't one. The best language for chat applications depends on each app's platform and requirements. If you’re planning to build a chat app, you need to figure out which programming language is best for you specifically. Identifying the language that perfectly fulfills your project’s requirements can significantly reduce both development time and cost.
In this article, we’ll be diving into the different programming languages you can use to develop a chat app. First, we'll explain the differences between front-end languages and back-end languages. Then, we’ll discuss the best options for both front-end and back-end languages and explore how your choice should depend on your app’s platform and requirements. Lastly, we’ll give you a list of questions to ask yourself to figure out what languages will work best for you.
Let’s get started:
Front-End vs Back-End Programming Languages
The front-end programming language is the language used to build the chat client. Simply put, the UI that your customers will use to send messages back and forth is all built with the front-end programming language. The back-end programming language, on the other hand, deals with everything behind the scenes. It powers the server-side code that handles authentication, routing, APIs, etc.
It’s possible for the front-end and back-end programming languages to be the same. A good example of this is JavaScript which can run both in a browser and on a server. However, most of the time, the two languages will be different. The front-end language will largely depend on the primary platform you choose for your chat app—as some platforms only support specific languages. The back-end language is almost always platform-agnostic and should be chosen based on its optimization features as well as your developers’ familiarity.
Best Front-End Programming Languages for a Chat App
Now that we know the difference between front-end and back-end languages, let’s start digging into the various front-end languages you can use for your chat app. As we mentioned earlier, the front-end language you choose will largely depend on which platform or platforms you want to support. Therefore, we've organized the following sections by platform, including languages for building Android, iOS, web, or cross-platform chat apps.
Android, iOS, and web each have their own specific programming language(s). This means, if you want to support all three platforms, you have two options. You can code and maintain three different codebases, or you can choose one of the cross-platform solutions. If you need to support multiple platforms, we recommend focusing on cross-platform solutions. Unless you are very well-funded, having three native solutions is not worth the cost if you’re just starting out.
Android Programming Languages
There are two official Android programming languages to choose from: Java and Kotlin.
Java
The original programming language of choice for building Android apps, Java has been around since 1996—basically forever in internet-terms. It's also popular outside of app development. Many legacy banking, retail, and entertainment systems are built with Java. And, because it’s an object-oriented programming (OOP) language, it is often used in universities to teach the concepts of encapsulation, abstraction, inheritance, and polymorphism. This means you won’t have any trouble finding developers who are familiar with Java.
Benefits of using Java:
Relatively easy to learn.
Object-oriented programming language, which allows for building modular components and reusable code
Platform-independent, which means it can run on any type of server
Chat apps built with Java:
Twitter’s Android client is built using Java
Signal, one of the most popular encrypted chat apps, uses Java for their Android client
Here’s a tutorial on how to build an android chat app in Java.
[
](https://www.cometchat.com/tutorials/how-to-build-an-android-chat-app-in-java)
Kotlin
The new kid on the block, Kotlin was released in 2016. Not just an official language of Android, Kotlin is also the preferred language by Google for Android development. Why? Well, while Java is an object-oriented programming language, Kotlin has both OOP and Functional Programming (FP) features. This makes it a great language to try out if you’re dabbling in functional programming. Another reason Google prefers Kotlin is that it’s statically typed and more concise than Java. This means you’ll be able to write less code and your code will have a lower chance of errors.
One of the most useful features of Kotlin is its 100% interoperability with Java—Kotlin can call Java functions and Java can call Kotlin functions. You can build an app that’s half-Java half-Kotlin if you’d like.
Benefits of using Kotlin:
Easy to read and understand
“Null-safe", which means your app won’t crash because of null pointer exceptions
Immutable, lowering the chance of developer errors
Interoperable with Java, which allows for a flexible development environment
Here’s a step by step tutorial on How to build an Android chat app in Kotlin.
[
](https://www.cometchat.com/tutorials/how-to-build-an-android-chat-app-in-kotlin)
iOS Programming Languages
iOS, just like Android, has its own unique programming languages for its platform. If you want to develop a native iOS chat app, you’ll have to choose from two primary languages: Objective-C and Swift.
Objective-C
Objective-C is an older language dating back to the early 1980s. It was the language Apple originally chose before they created their own language (which we happen to talk about next). Just like C++ and C#, Objective-C is based on the C programming language. It adds object-oriented capabilities to C. Anyone familiar with C will be familiar with the syntax of Objective-C.
While Objective-C won’t be going away for a while, you should seriously consider Swift if you’re planning on creating a native iOS app. We explain why in the next point.
Benefits of using Objective-C:
Offers automatic garbage collection
Objective-C’s expressive syntax allows for quick comprehension
Object-oriented programming language, which allows for building modular components and reusable code
Chat apps built with Objective-C:
WhatsApp’s iOS app is built using Objective-C
Nearly all iOS apps built before 2014 (when Swift was created) have at least some part of their codebase built with Objective-C
Swift
Apple spent years researching programming languages. They then combined that research with the lessons they learned while building the Apple Platform to create Swift. This programming language simplifies many of the common patterns from Objective-C such as closures, type inference, and generics.
Swift is a great choice for building native iOS apps. Unless you’re working with a legacy app that was built completely in Objective-C, we’d recommend using Swift for iOS development.
Benefits of using Swift:
Runs faster than Objective-C
Statically typed, which reduces developer errors
Prevents stack overflows and manages memory, both automatically
Completely open-source
Interoperable with Objective-C
Chat apps built with Swift:
We created an amazing video tutorial on building an iOS chat app using Swift with iOS Luke.
[
](https://www.cometchat.com/blog/build-an-ios-chat-app-with-swift-ui-kit)
Web Programming Languages & Frameworks
The only “real” programming language a browser can run client-side is JavaScript. So, you’re stuck with it. However, the JavaScript ecosystem is vast. There are many different JavaScript frameworks to choose from that will make development easier and faster. In this section, we’ll cover both vanilla JavaScript as well as a few different JS frameworks.
JavaScript
Plain vanilla JavaScript is always an option for building a web chat app. But keep in mind that building an entire client-side UI for a chat app from scratch is a huge undertaking.
With vanilla JS you don’t need to use a framework. However, since one of the biggest benefits of using a JS framework is the coding structure it enforces, you should plan to compensate for that by enforcing reusable, repeatable patterns and modules. This will keep your codebase from becoming a spaghetti nightmare.
Benefits of using JavaScript:
Relatively simple and easy to learn
Extremely popular and widespread
Very versatile, which means you can create rich interfaces using purely JavaScript
React
React is one of the most popular JS frameworks. Its focus on creating modular UI components makes it easy to quickly prototype a web app. There are also plenty of open-source libraries of ready-to-use React components, such as Material-UI, that make development even easier.
React also provides modern state management, which, given the complexity of a chat app, is a must.
Benefits of using React:
Component architecture allows for code reusability
Gives access to a “Virtual DOM” which decreases load time and increases flexibility
Easy to understand and learn if you’re familiar with JavaScript
Can easily be ported to React Native for mobile development
Need some inspiration? Here’s how you can build a fully featured react chat app.
[
](https://www.cometchat.com/tutorials/build-a-fully-featured-react-chat-app)
Angular
Another JS framework, Angular is a great choice for building a web chat app. It offers a standardized application structure that provides consistency to your project. Just like React, there are multiple libraries of ready-to-use, well-tested UI components that you can use to speed up development.
An interesting feature of Angular is that it's built with TypeScript—a superset of JavaScript that is strongly typed. The benefit of a strongly typed language is that it helps developers keep their code clean and readable. It’s easier to debug and find common type errors.
Benefits of using Angular:
Large developer community
Component architecture allows for code reusability
Can lazy-load modules, create a lightweight app
Lots of pre-built design libraries to speed up development
Check out this tutorial on building a chat app with CometChat’s Angular UI kit.
[
](https://www.cometchat.com/tutorials/build-whatsapp-clone-using-cometchat-angular-ui-kit)
Vue
Vue.js is an approachable JS framework that has a less steep learning curve than React and Angular. It’s also less opinionated, which means there are fewer restrictions and constraints in how you implement your project. One of the biggest benefits of Vue is that it’s only 20 kilobytes large, so it loads much faster than React and Angular.
However, since Vue is relatively new, it has less support and fewer available plugins. You’ll often have to resort to vanilla JavaScript to incorporate other JS libraries that only have React or Angular support.
Benefits of using Vue:
Small package size decreases load times
Large ecosystem of developer tools, which speeds up development and scaffolding
Gives access to a “Virtual DOM” which decreases load time and increases flexibility
Great run-time performance
Check out this tutorial to create a chat app with Vue.js.
[
](https://www.cometchat.com/tutorials/create-a-chat-app-with-vue)
Cross-Platform Programming Languages & Frameworks
If you’re building a chat app, chances are high that you'll want to support multiple platforms. As we mentioned earlier, your options are to either build and maintain three separate codebases or to use a cross-platform framework and have a single codebase that compiles into separate apps.
React Native
React Native, as the name implies, is a framework built upon React that targets native platform APIs. Since React Native wraps around native UI, the same React codebase compiles into two native apps. If you’re familiar with React, React Native will be easy to learn.
The major drawback of React Native is that it's meant to support mobile apps and doesn’t compile into a web app. So, if you want to support all three platforms you’d have to build and maintain a React Native codebase for the mobile platforms and a React codebase for the web platform.
That being said, many of the most popular chat and social media apps use React native for their mobile apps. Facebook, Pinterest, Instagram and Skype all use React Native.
Benefits of using React Native:
Allows for code reusability across mobile platforms
Very large community of developers
Easy to learn with a familiarity of JavaScript
Modular, component style architecture allows for easy code reusability
Chat apps built with React Native:
Skype’s mobile apps use React Native
Discord uses React Native for their iOS app
Instagram uses React Native for its iOS and Android apps
Ionic
Ionic is a very interesting and versatile cross-platform framework. It's framework-agnostic, which means you can use it with React, Angular, Vue, or even just vanilla JavaScript. Unlike React Native, Ionic will compile your codebase into a hybrid app for the app store and a Progressive Web App (PWA) for the web. A hybrid app is a web app embedded into a mobile app. It executes the same code, no matter the platform. A hybrid app looks and feels like a native app but isn't one.
Ionic provides the UI layer of your chat app. By itself, it doesn’t allow you to access native device features. However, Ionic does come with Capacitor, a framework that provides JavaScript plugins to access mobile device features such as FaceID, geolocation, Bluetooth, camera, and many many more.
Benefits of using Ionic:
Comes with a suite of native compatible tools allowing access to mobile device features
Front-end agnostic, which means you can use React Native, React, Angular, Vue, or any other framework
Large developer community
Capacitor
Created by the same team that built Ionic, Capacitor is the framework that allows you to access the native features of a mobile device. While Ionic projects come with Capacitor, they can both be used separately. You can use Ionic without Capacitor and you can use Capacitor without Ionic. You can drop Capacitor into any existing web app to convert it into a native mobile app.
Benefits of using Capacitor:
Provides PWA (Progressive Web App) support
Allows for native and web developers to work alongside each other
Widely used at the enterprise level
Best Back-End Programming Languages for a Chat App
Now that we’ve discussed front-end programming languages, let’s dive into the best back-end languages for a chat app.
The server-side language is not constrained by the client-side platform. This means, theoretically, you can use any back-end language to power your chat app. However, there are some important code features of a chat app that make certain back-end languages a better fit than others. These features are:
Real-time: messaging must seem instant to the user
Concurrency: the code must handle many simultaneous connections
Event-driven: most code execution is driven by users’ actions
Given these constraints, a few programming languages stand out:
Erlang
Erlang is a general-purpose, functional programming language that is designed for concurrency. It can handle many processes running at the same time. This makes it a great language for building a large, scalable chat app. Its concurrency is why the WhatsApp team chose Erlang for their chat app.
Benefits of using Erlang:
Offers concurrency through the use of lightweight process threads
Scalable both vertically, by adding more cores, and horizontally, by adding more machines.
Reliable because it can restart processes that crash due to bugs
Chat apps built with Erlang:
WhatsApp uses an erlang-based backend for its chat app
Facebook’s chat client is powered by an erlang server
Javascript
Yes, Javascript can run server-side as well as client-side. The server-side version of Javascript requires a Node environment to run. Javascript excels at event-driven code execution and real-time patterns via frameworks like WebSocket.
One of the biggest benefits of Javascript is that it’s one of the most popular programming languages and is well supported.
Benefits of using Node.js (javascript for servers):
Offers non-blocking I/O and asynchronous request handling
Rich ecosystem of plugins, frameworks, and open-source code
Very fast processing due to V8 engine
Chat apps built with Node.js:
LinkedIn primarily uses a Node.js backend for their mobile app
Go
Go, also known as Golang, was created by Google. It uses easy-to-read syntax to build highly performant apps. Just like Erlang, it’s highly concurrent, which makes it a great choice for chat apps.
Benefits of using Go:
Completely open-source
Automatic garbage collection makes memory management a non-issue
Offers concurrency by utilizing multiple cores
Chat apps built with Go:
Some of Slack’s backend functionality is written in Go
Twitter’s event queue in the backend is powered by Go
Which Programming Language Should You Choose?
So, which programming languages should you choose to build your chat app?
You have to select a front-end language, a back-end language, and possibly even a cross-platform framework. That sounds like a lot, but there's no need to get overwhelmed. Here are some questions to ask yourself:
Do I need to support both a web app and a mobile app?
If your answer is no, move to the next question.
If your answer is yes, then you should pair whatever Javascript framework you’re most comfortable with (React, Angular, Vue, or vanilla Javascript) with the Ionic framework. This will allow your app to be compiled into a hybrid app for mobile devices and the web.
Do I need to support both Android and iOS?
If your answer is no, you should just choose the best language for whichever platform you support. An Android app should be written in Java or Kotlin (or both). An iOS app should be written in Objective-C or Swift (or both). The choice between the platform-specific languages is entirely up to you and what your team is comfortable with.
If your answer is yes, then your best bet is to use JavaScript (React Native) to build one codebase that can be compiled into two separate native apps for Android and iOS.
What back-end programming language should I choose?
The best answer to this question is whichever programming language you and your development team are most comfortable with. Yes, some languages, such as Go, Erlang, and Javascript, have built-in benefits. But none of these benefits outweigh familiarity, which allows your team to develop with speed and efficiency.
Conclusion & Additional Resources
Just like every other part of building a chat app, choosing the best programming language for your chat app is no easy undertaking.
Hopefully, after reading this guide, you have a better understanding of what programming language is best for your specific use case and project requirements.
Once you have your programming languages picked out, head over to our tutorials section to see our large library of framework-specific guides and walkthroughs such as:
About the author
Cosette Cressler is a passionate content marketer specializing in SaaS, technology, careers, productivity, entrepreneurship and self-development. She helps grow businesses of all sizes by creating consistent, digestible content that captures attention and drives action.
Cosette Cressler
CometChat
