According to Statista, there are over 6 billion active users of smartphones, which is over 80% of the world's population. Why are these numbers significant you ask? Well, because that means there are at least 6 billion people using some form of a chat application on a daily basis.
What this actually translates to is that there are high app user expectations for usability, delight, and functionality for chat applications.
Below, we dive a little deeper into a breakdown of the chat app development design, usability, and most importantly the key features of modern day chat apps.
Understanding the chat app space
Chat apps are essential in helping bridge human connection. Without experiences like WhatsApp, Discord, Snapchat, Telegram, Slack, WeChat and the many other online chat apps out there, we would have less flow of information from person to person.
If you think about it, chat is the foundation of how humans transfer knowledge. Focusing on the problems that are being solved for on these major social networks and platforms can help us become better designers and technologists. If we can improve the user experience by focusing on what people find complex within online chat experiences, we can better understand what their basic needs are for knowledge transfer—and then in turn improve other real-time experiences because we understand our users' mental models.
Breaking down chat app experiences
What makes or breaks different chat experiences? Since there is a huge spectrum of app users with varying backgrounds and levels of familiarity with technology, it’s important to keep certain things at the forefront of our minds.
Ask yourself this:
- Is the experience usable?
- Are these features that the users need?
- How much work are we making our users do to learn how to use our product?
- Is user authentication easy?
Reinventing the wheel is a common issue for designers, developers, and engineers. To avoid this one should use proven design patterns and established best practices that align with users' mental models. This makes the experience more intuitive, reduces the need for users to think critically, and improves overall usability by meeting their expectations.
To create these experiences, analyze chat interfaces on the web and mobile and identify effective design patterns from popular messaging apps.
Common messaging apps used today
Discord
Discord, initially a voice chat platform for gamers, has grown into a community hub offering text, voice, and video chat. It allows users to create channels, send files, react to messages, and host events, all synced across devices.
Discord uses WebSockets for real-time communication. For voice and video calls, it employs WebRTC, enabling peer-to-peer connections to reduce server load. Text and media are handled via HTTP-based REST APIs with cloud storage for file transfers.
The platform's backend is built with Elixir for concurrency and Redis for caching, supporting horizontal scaling with Kubernetes and Docker. Media streaming uses Opus for audio and VP8/H264 for video.
However, Discord's reliance on WebSockets can strain bandwidth in large servers, and WebRTC can experience issues with network instability. Centralized servers for data management raise privacy concerns, as messages and media aren’t end-to-end encrypted. Large events or traffic spikes can also cause delays or outages.
Slack
Slack offers a robust team communication platform, integrating messaging, mobile push notifications, and voice functionality in a single interface. It enables users to initiate threads, react with emojis or custom "Slackmoji" stickers, and share files (including GIFs). The platform supports third-party API integrations, such as Microsoft tools, allowing seamless workflow automation. Additionally, Slack provides "Huddles," a lightweight, voice-based collaboration feature that enhances project management, similar to traditional phone calls but optimized for team interactions.
Messenger App
Messenger (formerly Facebook Messenger) has evolved into a standalone app, serving as a primary messaging client for mobile and web platforms. It includes features like real-time messaging, group chats, file sharing, message reactions, and conversation search.
Technically, Messenger uses WebSockets and long-polling for real-time communication, with proprietary protocols and HTTP-based APIs for both synchronous and asynchronous message delivery. Message synchronization across devices relies on cloud storage, while FB scalable infrastructure ensures reliability through message queues and failover mechanisms. The app built microservices architecture to handle load balancing and data consistency.
Messenger integrates third-party APIs for games, bots, and payments. Secret Conversations offers end-to-end encryption, enhancing security for private communications.
However, one limitation of Messenger from a technical perspective is its reliance on Facebook's centralized infrastructure, which can create potential bottlenecks and scalability challenges during high traffic events or outages. Additionally, the platform's integration of third-party services can introduce latency and security concerns depending on the external APIs used.
WhatsApp, with over 2 billion users, offers messaging, voice and video calls, and group chats, all protected by end-to-end encryption via the Signal Protocol. It uses WebSockets for real-time messaging, falling back on long-polling or HTTP requests when necessary.
WhatsApp’s backend is built on Erlang, which supports high concurrency and fault tolerance, while using XMPP (with customizations) for message exchange. For media transfers, it employs efficient HTTP-based file uploads. Voice and video calls leverage WebRTC for peer-to-peer communication, dynamically adjusting quality based on network conditions.
The app’s infrastructure is scalable, using distributed systems and load balancing across multiple data centers to ensure reliability. However, the reliance on centralized servers can cause bottlenecks during peak traffic where end-to-end encryption ensures message privacy, metadata is still accessible to WhatsApp. The app can also experience performance issues in areas with poor network conditions or high congestion.
Telegram
Telegram is known for its fast, scalable messaging platform with chat, voice, video, file sharing, and emojis. It uses MTProto, a custom protocol for real-time messaging, with long-polling and WebSockets for low-latency communication. Telegram’s default chats use server-client encryption, allowing Telegram to access messages, while Secret Chats offer end-to-end encryption for greater privacy.
The app uses a distributed architecture and cloud-based storage to sync messages across devices. Media transfers are handled via optimized HTTP APIs, ensuring efficient file sharing. Telegram’s scalability relies on servers across regions for fast access.
However, Telegram’s reliance on server-client encryption for default chats raises privacy concerns, and Secret Chats aren’t available for group chats. Additionally, the MTProto protocol, though efficient, has not undergone the same independent audits as other encryption standards, posing potential security risks.
Chat app features comparison
Based on our research, we've created a feature comparison chart showing that most popular messaging apps offer similar key features, indicating feature parity.
Some apps and APIs have additional features targeting different audiences, but what varies across apps are themes, UI layouts, and interactions. This is where prototypicality matters—familiar design patterns let users quickly start using the app without needing to learn new interactions. With feature parity across most chat apps, users expect common features as part of their mental model and user journey.
One example of a feature that ended up maintaining a similar design pattern across these different chat apps is message reactions (emojis). Message reactions are a way for users to show sentiment on new messages or specific messages. This pattern became popular in messaging apps after the rise of adding reactions on social media platforms. Now, almost all chat apps include message reactions in some shape or form.
Most used chat features
Including these popular online chat features creates a certain level of intuitiveness for users. If you’re looking to get started with these common features so you can attract and retain app users for the long-term, you’ve come to the right place.
To dive right in, check out our Chat SDK tutorial, our iOS and Android app tutorials or sign up for a free account to start building these must-have chat features.
