Slack Clone App Development: How To Build An App Like A Slack

Do you know how many organizations like yours are using Slack for internal communication? Over 750000 to 950000 companies.

79M Slack Monthly Active Users

47M+ Slack Daily Active Users

1M+  Organizations running on Slack

18%  Market Share of Team Collab Tools

Unfortunately, the of all these businesses are on Slack’s servers. To be straightforward, it’s with a third-party platform and data privacy is at risk.

Understanding the intensity of this concern, many organizations big and small are building their own internal communication systems similar to Slack, and manage their data on their own servers.

In this article, I’ll walk you through why your company needs a Slack clone, and a clean guide on how to build one even without a technical team.

Why Build Your Own Slack Clone Instead Of Using Slack?

The key reason why organizations are considering developing their own Slack-like app is the sum-effect of multiple factors. As an organization scales, the consumption of Slack’s resources increases.

With each additional team member, the cost of scaling up shoots. This is all while organizations risk their chat data to a third party.

Although Slack’s AWS servers support multi-tenant architecture, organizations still do not have the freedom to secure their messaging data as they prefer, or customize the platform as per their compliance requirements.

Let me list down the key benefits you’ll enjoy when building an app like Slack with your own team using a pre-built chat solution.

Using Slack	Building your own Slack
Data Ownership & Privacy Risks	Complete ownership of data & privacy
High, Recurring Costs	One-time license, lifetime access
Compliance & Security Constraints	Custom security, region-specific compliance
Product Customisation Limits	100% customization & control

Ultimately, Slack is an excellent collaboration tool, but not for organizations like yours looking for full control, customization and compliance.

 

Ready to Build an App Like Slack Using MirrorFly IM?

Book a Free Demo

What Is An IM Solution And How To Build A Slack Clone With It?

An IM (Instant Messaging) Solution is a software that comprises pre-built API (Application Programming Interface), SDK (Software Development Kit), UI Kit (User Interface Kit), dependencies, libraries, documentation and all the tools required to integrate instant messaging capabilities to an app or web.

The SDK primarily comes with pre-built codes that enable features like direct chat, voice calls, video calls, channels, presence/ typing indicators, push notifications, file sharing and all other chat features needed for internal team communication across enterprise organizations.

If your organization already has an app, or is planning to build one, using a CPaaS solution is a good starting point. It is the underlying engine that constructs the real-time communication infrastructure like Slack in your own platform, running on your own servers.

To be precise, here are two approaches to your Slack Clone Development:

1 – Custom Development from Scratch

In this approach, your team will write code line by line for every component including features like real-time messaging, presence indicators, file sharing and third-party integrations.

This gives full control over your architecture and is mostly suitable for enterprises that can comfortably fund this project for the long-term.

2 – Script-Based (White-Label)

When you choose this approach, you’ll purchase a pre-built enterprise instant messaging software like MirrorFly. This solution will contain a set of tools you will integrate into your existing app, or an MVP to enable workplace collaboration features within a short time.

This is one of the most cost-effective and fastest ways to build internal communication infrastructure. You can white-label it, and have complete control of the data, security features and platform.

Tech Stack For Instant Messaging App Development In 2026

Layer	Tech Stack
1. Client Layer
Frontend (Mobile)	Kotlin, Java, Swift, Flutter, React Native
Frontend (Web)	React, Angular, Vue.js, JavaScript, HTML5, CSS3
Chat & Calling SDK	MirrorFly Chat SDK, Voice SDK, Video SDK
2. Real-Time Backend
Messaging Protocol	XMPP (Ejabberd), WebSockets
Real-Time Communication	XMPP, WebSockets
Voice & Video	WebRTC, Janus Media Server
Backend APIs	Spring Boot REST APIs
3. Data Layer
Database	MySQL, PostgreSQL, Redis, Cassandra (optional)
Cache	Redis
Message Queue	RabbitMQ
Authentication	JWT, OAuth 2.0, SSO (SAML/OpenID Connect)
File Storage	Amazon S3, MinIO, Local Storage
4. Infrastructure Layer
Notifications	Firebase Cloud Messaging (FCM), Apple Push Notification Service (APNs), Web Push
Security	AES-256 Encryption, TLS/SSL, DTLS-SRTP
Deployment	Docker, Kubernetes, On-Premises, Private Cloud, Public Cloud
Monitoring & Logging	Prometheus, Grafana, ELK Stack
AI (Optional)	LLM Integration, AI Chatbot, Speech-to-Text, AI Moderation, AI Summaries

What are the Steps To Build A Slack Clone App In Flutter

Before building a Slack clone app in Flutter, ensure your development environment meets the required platform specifications:

• Android Lollipop 5.0 (API Level 21) or above
• Java 8 or higher
• Gradle 4.1.0 or higher
• targetSdkVersion 34 or above.
• compileSdk 34

The minimum requirements for iOS

• iOS 13.0

Step 1: Get License Key

Follow the below steps to get your license key:

• Create a free account on the MirrorFly Console. If you already have an account, simply log in.
• After signing in, you’ll be redirected to the MirrorFly Console Overview page.
• In the Application Info section, you can find your license key. Copy this key and use it during the integration process.

Step 2: Create Android Dependency 

Add the given code to the root build.gradle file inside your Android folder. This helps set up the required configuration for your app.

allprojects {
  repositories {
      ...
      ...
      jcenter()
      maven {
          url "https://repo.mirrorfly.com/release"
      }
  }

Make sure the following settings are added to the app/build.gradle file inside your Android folder.

android {
  compileSdk 34
  ...
  defaultConfig {
    ...
    minSdkVersion 21
    targetSdkVersion 34 // or higher
  }
}

Step 3: Create iOS Dependency

Add the following code at the end of your ios/Podfile. Make sure it is included before running the app setup process.

post_install do |installer|
  installer.aggregate_targets.each do |target|
           target.xcconfigs.each do |variant, xcconfig|
           xcconfig_path = target.client_root + target.xcconfig_relative_path(variant)
           IO.write(xcconfig_path, IO.read(xcconfig_path).gsub("DT_TOOLCHAIN_DIR", "TOOLCHAIN_DIR"))
           end
       end
  
  installer.pods_project.targets.each do |target|
    flutter_additional_ios_build_settings(target)
    target.build_configurations.each do |config|
      config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '12.1'
      config.build_settings['ENABLE_BITCODE'] = 'NO'
      config.build_settings['APPLICATION_EXTENSION_API_ONLY'] = 'No'
      config.build_settings['BUILD_LIBRARY_FOR_DISTRIBUTION'] = 'YES'
      config.build_settings["EXCLUDED_ARCHS[sdk=iphonesimulator*]"] = 'arm64'
      
      shell_script_path = "Pods/Target Support Files/#{target.name}/#{target.name}-frameworks.sh"
            if File::exist?(shell_script_path)
              shell_script_input_lines = File.readlines(shell_script_path)
              shell_script_output_lines = shell_script_input_lines.map { |line| line.sub("source=\"$(readlink \"${source}\")\"", "source=\"$(readlink -f \"${source}\")\"") }
              File.open(shell_script_path, 'w') do |f|
                shell_script_output_lines.each do |line|
                  f.write line
                end
              end
            end
     end
  end
end

Now, enable all the below mentioned capabilities into your project.

Goto Project -> Target -> Signing & Capabilities -> Click + at the top left corner -> Search for the capabilities below

Step 4: Create Flutter Dependency

• Enable all the capabilities listed below in your project settings.

dependencies:
  mirrorfly_plugin: ^1.5.0

• Run the flutter pub get command in your project folder to install the required dependencies. Then, use the following import statement to access all available classes and methods.

import 'package:mirrorfly_plugin/mirrorfly.dart';

Step 5: Initialize MirrorFly Plugin

• Add the initialization code in your main.dart file inside the main() function, before calling runApp().

void main(){
  WidgetsFlutterBinding.ensureInitialized();
  Mirrorfly.initializeSDK(
      licenseKey: LICENSE_KEY,
      iOSContainerID: iOS_APP_GROUP_ID,
      chatHistoryEnable: ENABLE_CHAT_HISTORY,
      enableDebugLog: ENABLE_DEBUG_LOG,         // to enable logs for debug
      flyCallback: (FlyResponse response) {
        runApp(const MyApp());
      }
  );
}

Step 6: Send a One-to-One Message

• Use the following method to send a text message to another user.

var textMessage = MessageParams.text(
    toJid: toJid,
    replyMessageId: replyMessageId, // Optional
    topicId: topicId, // Optional
    textMessageParams: TextMessageParams(messageText: messageText);

Mirrorfly.sendMessage(messageParams: textMessage, flyCallback: (response){
  if(response.isSuccess){

  }
});

Step 7: Receive a One-to-One Message

• These listeners are triggered only when a new message is received from another user. For more details, refer to the callback listeners section.

Mirrorfly.onMessageReceived.listen(result){
  // you will get the new messages
  var chatMessage = sendMessageModelFromJson(result)
}

Want to add more team communication features, check out this documentation.

Why Choose MirrorFly IM for Slack Clone?

To understand what MirrorFly offers to build an office chat app like Slack, you need an idea of the challenges you’ll face when building one from scratch.

For each practical roadblock, MirrorFly offers an enterprise instant messaging solution that most companies find relevant and easy to navigate in their Slack clone development projects.

Below listed are some of the concerns several organizations have raised over the years when building a Slack-like app, and how MirrorFly is helping the companies:

Challenge	MirrorFly Advantage
Building a messaging backend	Pre-built XMPP/Ejabberd infrastructure
Setting up voice & video	Integrated WebRTC SDKs
Scaling to thousands of users	Production-ready architecture
Implementing encryption	Built-in enterprise security
Launching quickly	Reduce development from months to weeks
Lowering engineering costs	Eliminate the need to build core communication infrastructure
Low/ No Customization	Full customization of features, workflows & security
Limited branding	Complete freedom to white-label with own logo & components
Security as-is	Options to customize security & privacy regulations
Data is in Slack’s servers	Complete data sovereignty
Limited access to dev tools	Full source code access
Hosting on Slack’s servers	Self-hosting on-premises, on cloud, or any server

MirrorFly IM Vs Slack: A Quick Comparison

To be clear, Slack is a ready-to-use team collaboration workspace, while MirrorFly is a CPaaS solution that helps build a collaboration platform like Slack. It offers easy-to-integrate APIs and SDKs that you can customize, white-label and deploy on your own servers. Here is a head-to-head comparison on both software:

Feature	MirrorFly IM	Slack
White-Label Solution	✅	❌
Self-Hosted Deployment	✅	❌
Full Source Code Ownership	✅	❌
Complete Data Ownership	✅	❌
Custom Security Policies	✅	❌
On-Premises Hosting	✅	❌
Cloud Deployment	✅	✅
Public & Private Channels	✅	✅
Direct & Group Messaging	✅	✅
Threaded Conversations	✅	✅
Voice & Video Calling	✅	✅
Large File Sharing	✅	✅
Unlimited Chat History	✅	❌*
Multi-Tenant Support	✅	✅
AI-Powered Features	✅	✅
Third-Party Integrations	✅	✅
Custom Branding	✅	❌
SDK & API for Custom Apps	✅	❌
SIP/VoIP Integration	✅	Limited
Dedicated Engineering Support	✅	❌

Cost To Make A Slack Clone Apps

The honest observation here is Slack seems like a budget friendly option at the first sight. But the cost is recurrent, with limited control over your data. As you scale, and look back at the compound of the monthly fee you’ve paid for internal communication, the number is going to be huge.

This is a factor that makes organizations rethink their decisions. Especially when the companies scale up, most of them regret not building their own chat infrastructure. 

Metric	From Scratch	MirrorFly
Timeline	4 to 6+ Months	48 hours to few weeks
Initial Investment	$50K to $250K+	$10K to $40K
Infrastructure Risk	High	Low
Engineering Effort	High	Moderate
Maintenance Cost	High	Lower
Time-to-Market	Slow	Fast
Break-even Point	~50K to 100K MAUs	No infrastructure break-even required

The ideal period to build your Slack clone is before you scale up to your next phase. The migration comes with transferring huge resources when it’s too late for the switchover.

What’s Next?

Slack is a giant in the team collaboration industry and building its clone is not an easy task, until you find the right solution like MirrorFly.

We’ve discussed everything we need to build a Slack-like app with the solution and if you’re ready to get started, it’s time to discuss your project with the experts – Contact Team MirrorFly.

Related Article:

1. WhatsApp Clone App Development in 2026
2. How To Build a Chat App for the Web?
3. Build a Video Conferencing App Like Zoom (2026 Guide)
4. How to Build an Instant Messaging App: Complete 2026 Guide
5. How to Build a Flutter Chat App with the MirrorFly SDK
   
   

Share it on