Magdalena Jackiewicz
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Magdalena Jackiewicz
Reviewed by a tech expert

How to build a custom instant messaging app – the ultimate guide

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With so many instant messaging apps available out there for business and private use, why would you want to build a new one? To redefine your company’s communication channels, or to connect with your customers or external collaborators, or reach brand-new audiences? Regardless of your goal or need, a custom chat app will bring your business a number of benefits and competitive advantages. 

An instant messaging app makes it more convenient and effective to run real-time conversations with your coworkers and clients. This is a must in every remote and hybrid work environment today. Emails aren’t as effective at such communication because of the formalities involved and many businesses are already shifting to chat software development to meet their goals.

Custom chat apps also offer brand-new ways to reach new customers. Over 3 bn people use this kind of software on a daily basis and that number continues to grow in a steady manner. If you don’t care about stats, jump straight to the next section. But here are a few numbers on the messaging app market worth being aware of:

Messaging app usage - key statistics. Source: Statista.
Messaging app annual users 2016-2021. Source: Business of Apps.
Most popular global messenger apps, according to Statista.

What exactly is an instant messaging app?

A messaging app is a real-time messaging software that enables simultaneous exchange of messages and information in cyberspace. It happens almost without latency.  

Instant messaging, enabled by apps like WhatsApp, WeChat or Facebook Messenger, is just one of the options available for users when it comes to real-time communication. Other options include: 

  • VoIP
  • internet relay chat
  • video and teleconferencing
  • robotic telepresence

It’s important to note that today’s chat apps don’t concentrate exclusively on the chat function, but offer video and audio communication options as well. More on this in further sections.

Now, let’s take a quick look at the architecture of chat apps.

Instant messaging app components

Every instant messaging app will deal with business requirements in its own way, but to describe the infrastructure in the simplest terms, we can narrow it down to two major components: the chat client and the chat server. 

A simplified structure of an instant messaging app.

Chat Client 

A desktop, web or mobile messaging app – the chat client will interact with a given operating system by e.g. sending push notifications, storing messages and files or displaying data to the user. It’s also what the user experiences. When they use the app to communicate, the chat client will transmit that message to the other major component: the chat server.  

Chat Server

The chat server (usually there are multiple) hosts everything that is required for the chat app to function, including the software, frameworks and databases, relevant APIs and media storage instances. Its purpose is to securely receive a message, identify the correct recipient, queue the message and subsequently forward it to the recipient’s chat client. 

Chat app architecture examples

We present an example architecture of a chat app, as well as the architecture built y WhatsApp.

Chat app - example architecture.
WhatsApp system architecture.

Must-have features of an instant messaging app 

Whether you’re building an app like WhatsApp or opt for a solution tailored to your workplace environment, you’ll have to include a number of features that are indispensable to ensure usability of your chat app. Consider the following:

  • Registration: you want to offer a quick and effective method to authenticate an account
  • Contacts: make importing contacts as seamless and easy as possible
  • Message statuses: users want to know whether their messages have been delivered and read
  • Group chat: including public or private group messaging, chatting in sub-groups or dedicated channels
  • Conversation history: users expect to have the ability to browse through messaging history
  • Security mechanisms: against personal data from theft (including identity theft) and hacker attacks.
  • Voice and video calls: instant messaging apps are increasingly replacing traditional voice calls
  • Voice messaging: similar to the traditional voicemail feature 
  • File sharing: for photos, GIFs, videos and stickers on a daily basis – users expect easy document sharing via instant messaging apps.
  • Push notifications: to inform about a new activity or communicate with app users

If you’d like to find out about other trending chat app features that will give your instant messaging app a competitive edge, head to our earlier article.

Advantages of a custom-built business messenger app over a third party chat app

I am not going to criticize the instant messaging apps available on the market – I happily use some of them myself, both privately and for business purposes. They have both advantages and drawbacks. My only intention here is to point out some of the cases in which a custom-built chat app may serve its purpose better than an off-the-shelf solution. Here are some of the scenarios:

When you want to support specific communities, target a specific audience

Different interest groups are finding it increasingly useful to communicate via dedicated chat apps. A custom solution for doctors and patients is just one example of a messaging app built to reach a particular target audience. When we consider specific subcultures, a chat app may serve as an excellent community builder that enables its members to discuss their hobbies and interests. The messaging app can then be further used to distribute relevant ads that the users would find useful, making your solution even more profitable. Besides, sticking to a specific target group can limit trolling and toxic behavior in cyberspace. 

When you want to offer niche functionalities

Solutions like WhatsApp, WeChat or Messenger offer a limited set of functionalities. In contrast, robust platforms like Slack offer many functionalities but a large proportion of them isn’t being used. If your goal is to offer functionalities that off-the-shelf solutions don’t have, you’ll have two options: either develop a brand-new platform from scratch, or integrate third-party functionalities. You’ll have to compare time and costs to understand which option will work better for your business case. 

When you need tightened security and/or privacy policies

Some organizations, e.g. government establishments, may need tightened security protocols or adhere to custom privacy policies. In such cases, off-the shelf solutions may not be able to meet these criteria. Some applications even sell private data to third parties or advertising providers. Above all, they are at increased risk of data leaks or hacker attacks.  

If you're willing to create an instant messaging app available only for users registered via corporate email addresses, you invest in a much better place to discuss company-related topics than a free-for-all chat app. It also creates a positive effect on employees and reduces the chances of business espionage.

When you need outstanding performance 

Older applications in particular often get bloated with legacy code required to support outdated versions of operating systems and ensure compatibility with an increasing number of device brands and models. Developing your own chat application that is future-proof, follows the current best practices and is established on a relevant tech stack will help eradicate this problem and ensure your chat app offers great performance. 

When you need specific design features

Mobile design has certain requirements, and the most important one is convenience in terms of reading and typing text using the on-screen keyboard. Some chat apps do not offer adequate comfort for specific target groups, do not ensure sufficient accessibility or do not support different screen resolutions. Custom UX/UI design will help you adjust your solution to the needs of your audience. 

When you’re tired of in-app advertising

While in-app ads are among the most popular chat app monetization strategies, excess advertising can ruin user experience completely. Popular messaging apps may annoy your users in the long run if the number of ads is ill-adjusted. 

When you prioritize excellent usability 

Some instant messaging apps offer only a limited usability free of charge; full usability is ensured via paid addons. This flaw is another result of an ill-considered monetization strategy. Some authors offer a useless stub of software under the pretense of a functional application, forcing users to pay to get it working.

Benefits of instant messaging apps for business

Instant messaging apps bring the global connection to the table and that’s indispensable for any international business that wants to thrive in the post-pandemic environment. I’m not saying that businesses depend on them completely, but a good chat application will bring other unexpected benefits that can highly increase operational efficiency. Consider the following:

Effective collaboration

Enabling collaboration is the fundamental concept of any instant messaging application. The video calling features in particular, serve to connect and offer a face-to-face discussion, whether it’s between internal employees or with a client. And since they are so common in today’s remote work environment, they also shape organizational culture and contribute to building a successful work environment. 

Improved work ethic

Real time chat apps allow employees to agree on goals and assign specific tasks to individual coworkers. Tagging them on these tasks allows them to easily monitor progress and notify the individuals who should take over once a specific task has been completed, helping to prioritize effectively. This will not only improve the employees’ mindset about their workplace and coworkers, but will also lead to our next point.  

Increased productivity

Whether we like it or not, we are prone to constant distractions from the many activities we engage in, the tasks we have, social media and simply the number of applications on our phones. A real time chat app will help users focus on what’s important and stay up-to-date with all developments without the need to go through a number of sequential emails.


Since email communication is becoming more demanding to use and doesn't offer real-time communication, they are becoming more inconvenient. A well-built and thought-through chat app will solve this problem for many businesses across different sectors. 


Using internet connection for cross-border conversation is much cheaper than traditional phone calls! But that’s not all there is – bringing people together remotely means you can limit your travel budget expenses and those related to office rentals. As people increasingly tend to work remotely, you may be able to reduce the office space you had before the pandemic and still have your employees work effectively. 

Automated reporting

Businesses that focus on achieving their goals will benefit from having the ability to track history of decisions and performance of the different units across the entire organization. Customizable reports delivered according to specific preferences will help make informed decisions on business-critical matters.

Streamlined communication with end users

Chat applications are commonly used to improve customer service. Customers increasingly prefer to solve their issues, so building a dedicated app for customers can improve your reputation and build trust. It can also provide you with insights about your customers and products or services that you offer. Above all, live consultants responding to customers over chat applications have proved to solve them more effectively than via phone or other means. 

Challenges to overcome when building an instant messaging app 

Every software development project has its challenges and chat app development has to face some issues and risks related to the nature of this software. When creating your own chat app, consider the following: 

Meeting the standards

Users expect that the chat app they select delivers a set of basic functionalities, including voice and video calling and file sharing. Building a real time communication software requires a lot of effort, as those real-time updates create a lot of synchronization issues, including server logic and database management systems. Sending the logic to the server may simplify the development process. 

Overloaded server

A chat application will always have users connected to it and that will impact server deployment – the more users, the more likely they are to overload the server. You have to optimize your entire setup, taking into account all the bottlenecks. Also, you have to make sure the servers interact correctly if you don’t want to risk losing data as you release new code. There must be a secure real-time connection with the server that stores all the messaging app history. 

Ensuring both security and privacy

Securing a chat app is a complex issue you should always consider before you start building your solution. 

One piece of the entire puzzle is the case of securing the messaging app itself. Users enter their personal data while they register to use the service and that’s already something extremely valuable for hackers. Also, because private data is involved, you’ll have to remain in compliance with a number of acts and regulations, depending on where the messaging app will be operational.

There is another piece of the puzzle involving security and its relation to privacy. To what extent should user conversations be monitored? Should they be forbidden to communicate privately altogether? Should full surveillance be acceptable?

All in all, everything in cyberspace is at risk of a potential hacker attack, so you will have to invest in tough security mechanisms. If you don’t own your internal team, hire an experienced messaging software provider that is familiar with the latest security practices. 

Right tech stack

If you don’t approach selecting the tech stack carefully, your messaging app may become outdated sooner than you expect and that may obviously cost you both time and money. Today’s world is unpredictable; the pandemic showed that businesses must be prepared to scale rapidly if they want to remain agile and competitive. The systems must be prepared to support increased traffic in huge channels without collapsing, at all times. 

Flawless app updates

App updates must be flawless – this is critical. A messaging app is constantly connected with users and processes their data on an ongoing basis. You cannot lose this data while you update your chat app or deploy new functionalities, or else you’ll lose the audience and trust. Configure the architecture properly and ensure the servers interact correctly – otherwise your data may be lost as you release new code. Also, there must be a secure real-time connection with the server that stores all the messaging history. 


Scalability of a real-time chat app is challenging and requires solid engineering skills. Facebook Messenger, for instance, handles hundreds of million concurrent users during peak hours. You can thus imagine that scaling the backend of a real-time chat application requires solid engineering skills and is highly dependent on the tech stack and set architecture. 

Every architecture component may become a bottleneck once you start serving a larger audience. It’s highly advisable to keep components independent so that they can be scaled on their own as required, without affecting the entire architecture. 

Stability of the connection

There are many reasons that can influence the stability of the network. Network loss may be caused simply by switching from smartphone internet and Wi-Fi. Messages can be lost even during such temporary breaks. A good messaging app should on the one hand be able to keep the connection stable and on the other, ensure that messages are reproduced once the connection is restored. 

How long does it take to develop an instant messaging app?  

The time required to develop a messaging app will be affected by your exact features you want to offer, the media and technologies you want to support (Do you require an iOS messaging app and an Android messaging app?), as well as scalability requirements. For that reason, it’s difficult to specify how much time is required to create a chat app.  

In addition, the design and complexity of the tool will also influence the timeframe, as well as the number of specialists and availability of resources. To understand how much time your project may take, discuss your needs with a messaging software development company (you can indeed contact us!). To give you a rough idea, we provide you some numbers on some basic features and processes involved in messaging app development below.

How much does it cost to develop a real-time chat app? 

It’s impossible to provide an exact estimate of developing an app like WhatsApp, as it will be influenced by a number of factors. The final cost of developing a messaging app depends mainly on the number and complexity of features. Basic features are easier to work with while advanced features take more time to build and thus will incur larger bills.  

Apart from the features, chat app costs will also be influenced by the scale of the project, which will affect the number of specialists involved in the process, such as interface designers and project managers. To understand what budget should be allocated to build and release a messaging app, consult an experienced chat app development company. We’ll be happy to put our expertise to work here as well. 

How to make profit off a custom messaging app?  

A free mobile messaging app has higher chances to attract a large audience immediately from its release. Because of this peculiarity, the most popular monetization strategies imply that the application is free by default and makes profit with a selected monetizing approach. Three most common include: 

Sell advertising space

You can sell video ads, splash screens or banners, but then you have to remember to balance the number and frequency of ads. Some audiences will be pissed off by seeing too many, although users accept them to an extent, as long as they can continue to use the service for free. 

Offer subscriptions

You give the users an upgraded version of your app at a monthly or annual rate. Typically, annual plans are better priced than monthly plans. With this monetization option, you need to offer customers as much flexibility as possible, so you can offer them quarterly or bi-annual billing plans. 

Offer in-app purchases

The clearest option for customers, as they know exactly what they buy. These purchases may refer to additional features, UI perks, extended cloud storage capacity, and other functionality that remain permanently on a buyer’s account.

Additionally, some of the less common monetization methods include: 

  • Chatbot integration: This is an advanced monetization possibility once your app gets user interest and base. It allows you to gain revenue from CTR (click-through rate) by providing relevant recommendations.
  • Sponsorship: In this model, revenue is generated via in-app sponsorship to create brand awareness. This method is best to utilize once you have a large-enough pool of app users.
  • Charging per download: You may use this method if you are sure to provide a unique and new app functioning, and you tested the hypothesis that users will purchase the app. In general, users buy only those apps that are very specific and have top performance.
  • Merchandise content: Creating chat themes, wallpapers and stickers related to any brand. The promotion of the brand brings win-win results for the app and the brand. 
  • Support official accounts: This type of instant messaging app is built for brands, public figures or celebrities who are willing to get close interaction with followers.
  • White label: This strategy supposes chat app development for enterprises’ internal use or customer support.

Building a custom instant messaging app in 2022

As you can see, there are a lot of issues companies must consider as they create their own messaging apps. The architecture must be well thought-through and the tech stack must be able to support large numbers of app users. 

In addition to real-time messaging functionality, a successful chat app will offer audio and video calls that support and have dedicated mobile apps available for users worldwide.

If you’d like to work with us on your messaging application software, contact me directly at and I’ll take it from there.

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