Creating a Telegram clone for Android: from idea to publication on Google Play

Creating your own messenger like Telegram is an ambitious task that requires not only technical skills, but also a deep understanding of the architecture of modern chat applications. Unlike simple clones WhatsApp or Viber, Telegram stands out open API, bot support, cloud storage and a unique encryption protocol MTProto. If you are planning to develop an analogue for Android, it is important to consider both backend components (servers, databases, protocols) and frontend implementation (interface, animations, notifications).

This article will help you understand the key stages: from choosing a technology stack to publishing in Google Play. We will consider three critical aspects that beginners often miss: the legality of using the MTProto protocol, optimization of working with large chats (100,000+ participants) and the integration of payment systems without blocking. If your goal is not just an educational project, but a full-fledged product, get ready for difficulties with moderation in app stores and protection against DDoS attacks.

1. Analysis of Telegram architecture: what needs to be copied and what needs to be improved

Before writing code, study how the original works. Telegram consists of several key components:

• 🔹 Client applications (Android, iOS, Desktop) - responsible for the interface and user interaction.
• 🔹 Server part (Telegram Server) - processes messages, stores media files and manages authorization.
• 🔹 MTProto protocol - provides encryption of traffic between the client and server.
• 🔹 Bot API - allows you to create bots for automation tasks.

For a clone, it is not necessary to copy everything “as is”. For example, you can simplify the server part using ready-made solutions like Firebase or Matrix, or replace MTProto with Signal Protocol (as in WhatsApp), if the priority is maximum security. However, please note: refusing MTProto will deprive you of compatibility with original Telegram clientswhich may be critical for some users.

One of the most difficult moments is working with media files. Telegram stores them in the cloud and optimizes them for different devices (for example, sends low-resolution video to weak smartphones). It is expensive to implement this from scratch, so many clones use Amazon S3 or Backblaze B2 to store files, and for compression they use libraries like FFmpeg.

⚠️ Warning: If you plan to use the name "Telegram" or its logo in your application, this violates trademark rights. Even if the code is open, branding is protected by law. An alternative is to come up with a unique name and design.

2. Choosing a technology stack for an Android client

There are several approaches to developing the client part on Android . The classic option is native development using Kotlin or Java using Android SDK. This gives maximum performance and access to all OS functions, but requires in-depth knowledge. Alternatives:

• 📱 Flutter —a cross-platform framework from Google that allows you to write code once for Android and iOS. Suitable if you plan to release an application on both platforms.
• 📱 React Native —popular among startups, but may be inferior in performance to native solutions.
• 📱 Capacitor/Ionic —hybrid applications based on web technologies (HTML/CSS/JS). The simplest option, but with limitations in functionality.

For working with the network and API, we recommend:

• 🔌 Retrofit — for HTTP requests to your server.
• 🔌 OkHttp — for low-level work with sockets (if you implement your own protocol).
• 🔌 WebSocket — for transmitting messages in real time time.

Pay special attention data storage. Telegram caches messages and media files on the device to save traffic. To do this, you can use:

• 🗃️ Room — for a local database (SQLite).
• 🗃️ DataStore — for storing settings (replacement SharedPreferences).
• 🗃️ Glide/Picasso — for loading and caching images.

3. Server part: how not to spend millions on infrastructure

The server Telegram is written in C++ and is optimized for processing millions of connections. Repeating this from scratch is unrealistic for a small team, so let’s consider alternatives:

Solution	Pros	Cons	Cost
Ready backend (Firebase, Supabase)	Fast development, scalability	Customization restrictions, traffic fees	From $0/month (freemium)
Self-hosted server (Node.js + MongoDB)	Full control, flexibility	Difficulty in support, DDoS risks	From $5/month (VPS)
Open-source alternatives (Matrix, XMPP)	Free, community, plugins	Not always compatible with the Telegram API	$0 (self-hosting)
Renting a dedicated server	High performance, security	Expensive, requires administration	From $100/month

For testing, you can start with Firebase: it provides Realtime Database for chats and Cloud Functions for processing logic. However, as the audience grows (10,000+ users), the cost can exceed $1000 per month. An alternative is to deploy your server on DigitalOcean or Hetzner using:

• 🖥️ Nginx — as a reverse proxy and load balancer.
• 🖥️ Redis — for caching sessions and messages.
• 🖥️ PostgreSQL — for storing user data.

To encrypt traffic you can use:

• 🔐 MTProto —the original Telegram protocol (requires a license).
• 🔐 Signal Protocol —an open standard used in WhatsApp.
• 🔐 TLS 1.3 —sufficient for basic protection (but does not provide end-to-end encryption).

⚠️ Attention: If you plan to store user data (phone numbers, messages), make sure that the server meets the requirements GDPR (for the EU) or 152-FZ (for Russia). Otherwise, you may be fined for violating confidentiality.

4. User registration: SMS, email or blockchain?

Telegram uses phone numbers for registration, which simplifies user identification, but requires integration with SMS services. Alternative methods:

• 📧 Email —easier to implement, but less reliable (many fake accounts).
• 🔑 Social networks (Google, Apple ID)—convenient for users, but depends on third-party services.
• 💰 Blockchain (Web3) — registration through a crypto wallet (for example, MetaMask). Suitable for decentralized messengers.

To send SMS codes you can use the following services:

• 📱 Twilio — reliable, but expensive ($0.01–$0.05 per SMS).
• 📱 Nexmo (Vonage) — cheaper, but less coverage of countries.
• 📱 Local providers (for example, SMS.ru for Russia) - beneficial for specific regions.

Example code for sending SMS via Twilio (to Node.js):

const accountSid = 'YOUR_ACCOUNT_SID';
const authToken = 'YOUR_AUTH_TOKEN';
const client = require('twilio')(accountSid, authToken);

client.messages.create({
body: 'Your confirmation code: 12345',
from: '+1234567890', // Twilio number
to: '+0987654321' // User number
}).then(message => console.log(message.sid));

What to do if SMS does not are they getting there?

The problem may be blocking by the operator (especially for virtual numbers) or service restrictions. Solutions:

1. Use a backup channel (email or push notification).

2. Connect several SMS providers for fault tolerance.

3. Invite the user to enter the code manually (for example, from a Telegram bot).

5. Implementation of chats: from simple to complex

Basic chat functionality includes:

1. Sending and receiving text messages.
2. Displaying delivery status (✅✅).
3. Support for media files (photos, videos, documents).
4. Notifications about new messages.

For this you will need:

1. Create WebSocket connection between the client and server.
2. Implement message storage in the database (with indexes for quick search).
3. Configure push notifications via Firebase Cloud Messaging (FCM).
4. Add synchronization between devices (if the user is logged in on several gadgets).

Example of message structure in the database (JSON):

{
"id": "msg_12345",
"chat_id": "chat_67890",
"sender_id": "user_111",
"text": "Hello! How doing?",
"timestamp": 1672531200,
"status": "delivered", // "sent", "read"
"attachments": [
{
"type": "image",
"url": "https://storage.example.com/img_123.jpg",
"thumbnail": "https://storage.example.com/thumb_123.jpg"
}
]
}

For group chat, add:

• 👥 Member management (adding/deleting).
• 👥 User roles (administrator, moderator).
• 👥 History of changes (who edited and when messages).

6. Security: how not to repeat the mistakes of other messengers

The main threats to the messenger:

• 🕵️‍♂️ Traffic interception (MITM attacks).
• 💣 DDoS - attack on the server to shut it down.
• 🔓 Data leak (for example, due to weak passwords in database).
• 🤖 Spam and bots —automated accounts for mailing.

Protection measures:

• 🔒 Use end-to-end encryption (E2EE) for secret chats.
• 🛡️ Configure DDoS protection (for example, Cloudflare).
• 🔑 Implement two-factor authentication (2FA).
• 🚫 Add content moderation (spam filtering, prohibited materials).

Example of setting Cloudflare for DDoS protection:

1. Register a domain and redirect it to the server via Cloudflare.
2. Enable the option Under Attack Mode in the security settings.
3. Set up rules WAF (Web Application Firewall) to block suspicious requests.

⚠️ Attention: If your messenger is used to transmit confidential information (for example, business correspondence), you may be required to provide data to law enforcement authorities upon request. This depends on the jurisdiction in which your company is registered.

7. Testing and publishing on Google Play

Before release, test:

• 🧪 Functional - check all features (sending messages, calls, notifications).
• 📱 On different devices (Android 10–14, various manufacturers).
• 🌍 Under different networks (Wi-Fi, 4G, weak signal).
• 🔍 On vulnerability (check for SQL injection, XSS).

For publication in Google Play prepare:

• 📝 Application description (in Russian and English).
• 🖼️ Screenshots (minimum 2, preferably 5-8).
• 🎥 Promo video (optional, but increases conversion).
• 📋 Privacy Policy (required!).

Cost of publication in Google Play Console — $25 (one-time payment). The moderation process takes from several hours to 3-5 days. Frequent reasons for rejection:

• 🚫 Infringement of intellectual property rights (design similar to Telegram).
• 🚫 Lack of privacy policy.
• 🚫 Inconsistency with age rating (for example, lack of content filtering for children).

8. Monetization: how to make money on the messenger

Main monetization models:

• 💳 Premium subscription - payment for additional functions (as in Telegram Premium).
• 🎁 Paid stickers/emoji - purchase of packs within the application.
• 📢 Advertising —banners or targeted messages (risk of losing users).
• 🤖 Paid bots —for example, a bot for business with advanced functionality.
• 💰 Cryptocurrency —integration of wallets (for example, TON Wallet as in Telegram).

Pricing example:

Function	Cost (per month)	Target audience
Premium account (no extra water, large files)	$2.99–$9.99	Active users, business
Pack of stickers (1 set)	$0.99–$1.99	All users
Bot for automation (for example, for stores)	$5–$50	Small and medium businesses

To accept payments, set up:

• 💳 Google Play Billing — for in-app purchases (commission 15–30%).
• 💳 Stripe/PayPal — for subscriptions on the website.
• 💳 Local payment systems (for example, YuKassa for Russia).

⚠️ Attention: If you plan to work with cryptocurrency, make sure that this is allowed in your jurisdiction. In some countries (for example, China), crypto transactions are prohibited.

FAQ: Answers to frequently asked questions

Can I use the Telegram source code for my project?

Yes, Telegram publishes the source code of client applications on GitHub under license GPL v3. This means that you can modify the code, but you must open source your project if you distribute it publicly. The server part (Telegram Server) is closed.

How much will it cost to support a messenger with 10,000 users?

Approximate costs:

• 🖥️ Server: $50–$200/month (depending depending on the load).
• 📧 SMS verification: $10–$50/month (10,000 SMS at $0.001–$0.005 per piece).
• 🔒 DDoS protection: $20–$100/month (Cloudflare Pro).
• 📤 File storage: $10–$50/month (1 TB on Amazon S3).

Total: $90–$400/month.

How to bypass messenger blocking in some countries?

If your service is blocked (as Telegram in Iran or Russia), you can:

1. Use proxy/VPN (for example, build support SOCKS5 into the client).
2. Disguise traffic under HTTPS (as Telegram does using Domain Fronting).
3. Place servers in neutral jurisdictions (for example, in Iceland or Switzerland).

However, these methods may be prohibited by local law.

Do you need a license to create a messenger?

In most countries a license is not requiredif you are not engaged in:

• 📡 Providing telecommunications services (as a telecom operator).
• 💰 Financial transactions (if integrate payments, you may need a license).
• 🔞 Distribution of prohibited content (for example, in China or the UAE).

We recommend consulting with a lawyer if you plan to monetize or work in strict jurisdictions.

Is it possible to make a Telegram clone without server?

Technically yes, but with serious limitations. Options:

1. P2P messenger (like Session or Briar) - messages are transmitted directly between devices. Minus: users must be online at the same time.
2. Decentralized network (for example, based on IPFS or Matrix). Disadvantage: difficulty in setting up and low speed.
3. Local network (Wi-Fi Direct, Bluetooth). Android client

For a full-fledged messenger, a server is still required.