How to Create a Chat App like WhatsApp: The Extensive Guide

Yellow
12 min readApr 23, 2021

The way we couldn’t imagine our life without phone calls a decade ago is the same way we can now hardly imagine it without instant messaging. Today it’s hard to find someone who doesn’t use chat apps at all or has never heard of them. Facebook Messenger, Telegram, WeChat, Snapchat — the chat market acquired some big players that already skimmed the cream off. The question of how to create a WhatsApp clone is really urgent today. Almost all smartphones have a chat app installed, usually more than one, and each minute their users send billions of text messages, memes, and funny videos to each other.

WhatsApp is one of the most influential and popular instant messaging apps. Founded in 2009, this app has already won the attention of a lot of users, more than 80% download it to stay in touch with their loved ones.

Several factors contributed to its fame, but the most important of them are the following:

  • First of all, the app’s affordability — WhatsApp is free-to-use.
  • Second, accessibility — the app is platform-agnostic and requires nothing more than an active internet connection.
  • Finally, worldwide usage — it allows fee-free international calls and works almost all over the world.

The pandemic that started last year actually brought some positive changes to the market. Working from home and self-isolating played a huge role in chat apps popularity skyrocketing. The success of big players like WhatsApp made a lot of entrepreneurs nurture the idea of making a chat app. So, how do you enter the market successfully and make your idea likable for potential users?

WhatsApp statistics for you to know

If you still have some hesitations about building a chat app like WhatsApp, here are some distinctive numbers that will show you what your idea can potentially turn into, other things being equal.

In 2020, this metric reached an incredible 2 billion monthly active users. Taking into account the previous 1.5 billion users milestone reached in 2018 and 1 billion reached in 2016, WhatsApp acquires half a billion users each two years. It’s slowly crawling up to Facebook, the most popular social media platform, which right now has 2.80 billion monthly active users. Impressive, isn’t it?

In March 2021, the app was downloaded 12 million times and ended up in the top five most installed non-gaming apps. WhatsApp goes ahead of Zoom, Telegram, and Facebook Messenger. Also, the platform preferences changed: compared to the previous March, iOS users started paying more attention to WhatsApp than Android users.

We already mentioned it as one of the leading factors that contributed to WhatsApp’s popularity, and here is the proof: this chat app is available in over 180 countries and 60 different languages. Africa seems to be the most popular region for WhatsApp market presence, with 97% in Kenya and 96% in South Africa. Then there is South America, where Argentina has 93% and Colombia has 92%. Europe is the third region that makes up the top 15 countries of WhatsApp’s penetration level, with 85% in the Netherlands and around 83% in Spain and Italy.

In 2017, WhatsApp introduced Status, which is quite similar to Instagram and Snapchat stories. Even though its launch may have been questionable, the popularity of this feature is growing: in 2019, around 500 million people were using Status daily, and now this number may be even higher.

WhatsApp Business is a messaging app that was launched in 2018 for allowing small businesses to establish smoother and more precise communication with their customers. It has labels, chat filters, automated messages, and catalogs for helping businesses organize their customer service. Only a year after its release, it reached the 5 million users mark. Also, for medium and large enterprises there is a WhatsApp Business API that connects businesses with their clients all over the world.

Facebook acquired WhatsApp for $19 billion, and right now, its revenue is estimated to be from $5 billion to $15 billion. Also, it’s worth mentioning that before being acquired by Facebook, WhatsApp got two large investments from Sequoia Capital: $8 million in 2011 and $52 million in 2013.

All these numbers clearly state that the chat app market is profitable and attractive for investors. With the right approach to development, it’s possible to meet all the audience’s needs and approval. The best way to start building a development strategy for a chat app is to define the list of possible functions that your potential app will have.

What features you may use for a WhatsApp clone app

The functionality of your chat app will define most of the future development process: tech stack, obstacles that may be faced, team size, and potential costs. Some features are considered must-haves for a chat app because they define its main purpose, so they are suitable for MVP or a basic app version, for example. Other functions make the app stand out from the crowd and add more uniqueness. Let’s take a closer look at what you can implement in your project.

Must-have functions

So, what should your chat app undoubtedly have to get a warm welcome from the audience?

User sign-in/log-in

Most apps, not only chats, start with authorization. There are a lot of ways users can make a profile: via phone number (which is the most popular way), social media, or email. You can implement only one way of authentication, however, making more options for sign up more appreciated by users since they can choose an option they’d prefer.

Contact import

This feature contributes a lot to the app’s user-friendliness. The ability of a chat app to import contacts from your device will make it extremely convenient and free users from the monotonous task of adding numbers to the new app. It would be even better if this process is automatic and kind of backstage.

Messaging

Well, this point is kind of obvious: a chat app cannot exist without its main function. Besides text messaging itself, there are several items to consider while developing this function:

  • Message status — everyone wants to know if their addressee received the message, read it, or edited some of their own.
  • Group chats — it’s always fun to stay connected in one virtual space with your family and/or friends.
  • Search — users don’t want to scroll the entire conversation to find a message.
  • Voice messaging — this feature can become a very useful option for users when they are in a rush or want to express emotions more clearly.

Profile customization

People want to show their individuality in all possible ways, and your chat app should not be an exception. It’s good to implement simple profile customization, like adding an avatar photo or creating a unique username.

File sharing

Today, it’s hard to imagine a chat app that doesn’t allow users to share photos, videos, and other types of files in a chat. This feature will require permission to access device storage and a fast file transfer system.

Storage

Texts and files sent must be stored, so users can access them anytime, and storing them on the users’ devices may not be a good idea. Cloud services are a better option: the device’s storage is not clogged, and all messages are easy to access.

Push notifications

In today’s unstoppable flow of information, people want to be notified about messages from others, so push notifications are a must for a chat app. But don’t forget to enable a muting function, either complete or partial because sometimes they can become a distraction.

Location integration and sharing

This feature can be handy when you are looking for a meeting point or get lost in an unknown place. You can send your location to a friend, and they can help you out.

Killing features

We finished with the functions that will become the base of your chat app. Now, let us show you some level-up features that can become your competitive advantage on the market.

Advanced customization

Sometimes, avatar photos and usernames are not enough. Users also can change chat background, choose a color palette for an interface, change text fonts, and search for funny stickers (or even create them).

Voice and video calls

Call integration is a useful feature for chat apps. It allows users to save money on mobile calls and talk to each other in real-time. Also, implementing group calls can present an advantage.

Broadcasting

Message broadcasting is not the same as group chats, since when you broadcast the message, you send it to all of them separately. There is no way other recipients can know who else got this message. Such a feature can find its recognition among news agencies or bloggers who can communicate with their fans in a more personalized way.

Now that we have defined the list of features to implement, it’s time to start building an app!

Main steps on how to build an app like WhatsApp

App development is a complex process that can be divided into several main stages. Here is the list of steps to follow for creating a WhatsApp-like app that will be successful among users:

Step #1: Choosing a business model

The very first step to take is to conduct some research and choose the right business model for your project. That will help you define potential challenges and some market insights that will come in handy while building a chat app like WhatsApp. What should you consider in this step?

  • Target audience. Who will primarily use your app: Gen Z or millennials, business people or students, family members, or strangers.
  • Monetization strategy. The way your app will make money. We will talk about it in detail a bit later.
  • Competitors. Knowing who you compete with will give you an understanding of what you can offer the audience.

Step #2: Finding a partner

When the set of features is defined and the business model is set, it’s time to choose a development agency that will help you realize your idea. While choosing a partner, pay attention to their experience, location, and the number of staff. The team should have relevant experience and understand the business needs of your project. Also, location and staff count will be some of the most influential factors for their hourly rate.

Step #3: Development

The best way to develop a good product, whether it’s a chat app or a trivia game, is to start with an MVP. This stage will allow you to understand if the audience needs what you offer them and if they have something in mind that you hadn’t thought of.

Step #4: Testing

Several testing options can help you see if everything is working seamlessly:

  • Unit tests — a way of testing the smallest piece of code that can be isolated as an entire system — a unit — independently.
  • Load tests — a type of performance testing that checks the reaction of an app to user actions under various loads.
  • Manual tests — a process where a special person — a QA engineer — plays the role of the end-user, using most of the app’s features.

Also, it will be useful to conduct A/B testing that will define the most pleasing design for your potential users.

Step #5: Launch and further support

When all the development and testing are finished, the app is ready for release! But it doesn’t mean that the work is over. Now, the users will flood you with feedback on user experience and bugs, so fixing and updating will then be your main focus.

Technology stack and requirements

Choosing the right tech stack for your app is the most important part of the development process. Technologies will define the speed of development, its cost, and the possibility of scaling up. Still, with so many options to choose from, how do you go with the right tech stack and not make a mistake?

What technologies WhatsApp used

First of all, let’s get an insight into what WhatsApp used to create the app.

  • Backend: Erlang, PHP, custom XMPP
  • Operating system: FreeBSD
  • Web-servers: YAWS, Lighttpd
  • Database: Mnesia
  • Offline database: SQLite
  • Virtual machine with customized patches: BEAM
  • Hosting: Facebook Data Center

Erlang is one of the rarest programming languages and is extremely useful for building chats with multiple simultaneous users and no downtime. Also, FreeBSD was chosen as an OS because of its appropriate requirements for safety and reliability.

Technical requirements you need to keep in mind

The choice of the tech stack should be driven by the potential features you want to implement and challenges you want to avoid. Let’s dive into the most significant parts of WhatsApp-like app development.

Privacy and Security

First of all, laws. Please be sure to follow all the legal requirements of the countries you want to release. For Europe, it’s GDPR — General Data Protection Regulation, and the US has HIPAA — Health Insurance Portability and Accountability Act.

Also, since the privacy of user data is an imperative topic today, it’s important to pay extreme attention to how the security feature on your app is built. It can be complicated to implement since there are still possibilities for third-party accessibility, but the technologies continue to get more and more innovative, so choosing the right solutions for privacy and security is not going to be hard.

UI and UX

The interface of your app should be simple and intuitive. There shouldn’t be any long tutorials that users have to go through. The simpler, the better: people should be able to just pick up the contact and start chatting! Also, if you are going to create a chat for multiple devices, make sure to use a responsive design, so users won’t have any trouble moving from one screen to another.

Cloud Sync

Cloud synchronization is extremely important these days. No one wants their device to be clogged with a lot of cache or files, and at the same time, they want everything being saved. Cloud sync will keep all texts, images, videos, and other files in one place without occupying the device space. So if someone changes or loses their device, everything will be available from the new one.

Recommended tech stack for WhatsApp-like app development

The tech stack for separate platforms would be different, so here are the possible variants for you.

Android

  • Programming language: Java, Kotlin
  • Storage: Core Data
  • Social authentication: Facebook SDK
  • Calling: WebRTC

iOS

  • Programming language: Swift, Objective-C
  • Storage: SQLite
  • Social authentication: Twitter
  • Calling: WebRTC

Backend

  • Programming language: Ruby, JavaScript
  • Web server: Nginx, Puma
  • Hosting: Amazon Web Services

Monetization strategy

There are several options for your chat app to make money:

  • Subscription. It’s not going to be the best option since most chat apps are free to use.
  • In-app purchases. You can implement buying of additional functions and content, like paid stickers or in-app minigames.
  • Advertising. It’s the most common and probably the easiest way to monetize your app — just show some ads to users. But don’t go too far with it, since a lot of users often find ads annoying.

Challenges you may face

There are a few points to consider while building a new chat app:

Attracting the audience

Sure, one of the biggest challenges is going to be attracting users to your solution. It should address the maximum amount of users’ needs, also, the app should be flexible and responsive to feedback.

All-in-one app

A lot of users expect their chat to be more than a chat. Launching ad campaigns, making one-to-one payments, applying chatbots, playing games — all this is supposed to be present in a modern chat app.

Being a “normal” app

It seems hard to make a chat app stand out from the crowd. You need something extremely attractive so users will choose you over other mainstream chats. Adding one or two unique features will draw the additional attention of the audience.

How much does it cost to develop an app like WhatsApp?

WhatsApp is considered to be a complex chat app since it has already existed for quite some time and managed to widely expand its functionality. Building it from scratch might be a waste of time and money, so starting with an MVP is a better approach. Approximately, the costs of a WhatsApp-like chat app will start from $10,000-$30,000. The actual cost will depend on the project’s specifications, the number of specialists, and the tech stack.

To sum it up

The chat app market is booming now, so it’s the perfect time to enter it! Besides the regular features, be sure to add something that will make your app unique. Don’t forget the security issues and implement an intuitive UI and UX — and your chat app is ready!

Originally published at https://yellow.systems.

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Yellow

A team of engineers writing about web & mobile applications, here’s how we think (https://yellow.systems/blog) and live (www.instagram.com/yellow.systems/)