Replacement Guide

How to Build Your Own Threema

Replace Threema with a custom build. Secure Communication For Individuals and Companies

Weekend Project
36 features0 integrationsOne weekend

Estimated Timeline

Based on 36 features at Weekend Project difficulty, expect about One weekend with AI-assisted development.

1
Setup & scaffolding
2 hours
2
Core features
4-6 hours
3
Polish & deploy
2 hours

Recommended Tech Stack

Next.js 14

Full-stack React framework with API routes and server components

Supabase

PostgreSQL database, auth, and real-time subscriptions

Tailwind CSS

Utility-first styling for rapid UI development

Pusher / WebSockets

Real-time messaging and live updates

Key Features to Replicate

Top features across 8 categories. See all 36 features

Security(8 features)

Contact Verification

Verify contacts using QR code to protect against man-in-the-middle attacks

DUALLOCKPremium

Block app access remotely to protect chat content when smartphone is lost or compromised

End-to-End Encryption

All messages, calls, and files are protected with strong cryptography based on open-source encryption technology

Open Source Code

Transparent code with regular external security audits demonstrating high security standards

Perfect Forward Secrecy

Prevents retrospective decryption even in the event of key compromise for reliable protection of confidential communication

+3 more in this category

Collaboration(7 features)

Distribution Lists

Send messages to multiple recipients at once without group functionality

File Sharing

Send any type of file with end-to-end encryption

Groups

Send messages to multiple recipients with strictly decentralized group management where only group members know membership

Location Sharing

Share location information securely within encrypted conversations

Media Sharing

Share images, videos, and other media with end-to-end encryption

+2 more in this category

Messaging(4 features)

Emoji Reactions

React to chat messages with emojis without triggering push notifications on recipient's end

Text Formatting

Add typographical emphasis with bold, italic, and strikethrough formatting

Text Messages

Send and receive text messages with ability to edit and delete after sending

Voice Messages

Send audio messages as a quick alternative to typing

Client(3 features)

Desktop App

Secure desktop application for chatting with full access to chat history, contacts, and media files

Tablet Support

Use Threema on tablets and devices without a SIM card

Web Client

Browser-based client for secure chatting with full functionality equivalent to mobile app

Communication(3 features)

Group Calls

Invite group members to join end-to-end encrypted audio/video group calls with single tap

Video Calls

Place encrypted video calls with brilliant video quality and tap-proof encryption

Voice Calls

Place encrypted calls without revealing phone number with crystal-clear voice quality

Customization(2 features)

Light and Dark Theme

Choose between light or dark theme for the user interface

WHITELABELINGPremium

Customize app design with flexible app name, individual logo, and color scheme to match corporate branding

Integration(2 features)

Contact Synchronization

Optional contact synchronization without requiring address-book access

EASYCONNECTPremium

Enable secure communication with external contacts via QR code without complicated registration

Privacy(2 features)

Anonymous Communication

No requirement for phone number or email address; uses unique Threema ID for confidential communication without revealing identity

Minimal Metadata

Messages disappear from servers after delivery; contact lists remain on user device to minimize digital traces

Cost Calculator

Pricing data not available for Threema. Check their website for current pricing.

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