Threema OnPrem. Self-Hosted

Threema OnPrem is a self-hosted messaging platform designed specifically for organizations that demand absolute data ownership, maximum privacy, and secure communication. Ideal for government agencies, police forces, critical infrastructure, and large enterprises, Threema OnPrem brings together Threema's trusted security architecture with full on-premise hosting—making it one of the most confidential and independent messaging environments available today.

Total Data Control & Network Independence

With Threema OnPrem, all data—including metadata—remains within your organization's servers. The system operates even in the absence of public networks, making it a reliable tool for crisis management and emergency communication.

Closed System, No External Connections

Unlike conventional messengers, Threema OnPrem operates in isolation from public networks. This means no third-party access and no unwanted data exposure, providing a completely private ecosystem for your internal communications.

Seamless Integration into IT Infrastructure

Easily integrate Threema OnPrem into your existing IT and security infrastructure. It offers MDM support, BYOD compatibility, and centralized admin tools, giving your IT team complete control over permissions, usage statistics, and configurations.

Cross-Platform Compatibility

Available on iOS, Android, desktop, and web, Threema OnPrem ensures consistent functionality across all devices. Desktop users benefit from features like chat history sync, media access, and even screen sharing during calls.

Communication Features

One-on-One & Group Chats

Send editable and deletable messages, or chat via voice and video calls—all end-to-end encrypted. Group chats and distribution lists allow secure communication with multiple users without exposing membership data.

Built-In Polls

The polling feature makes it easy to collect feedback from teams in real time, perfect for efficient decision-making.

Media & File Sharing

Share any file type with end-to-end encryption, including images, documents, and locations.

Encrypted Calls & Group Calls

Threema supports audio/video calls without revealing phone numbers. Group calls can be initiated with one tap, and the screen sharing feature on desktop adds a layer of productivity.

User-Friendly Features

· Private Chats: Lock sensitive chats with a fingerprint or PIN.

· Reactions: Use emoji reactions without triggering notifications.

· Themes: Choose between light and dark modes.

· Tablet Support: Use Threema on SIM-free devices or tablets.

· Anonymity: No phone number required—stay private and secure.

· Message Editing/Deleting: Correct or remove messages, even on the recipient’s device.

· Contact Verification: Prevent MITM attacks by verifying contacts via QR codes.

· Optional Contact Sync: Enable it only if desired—your address book stays private.

Important Note

Threema OnPrem is an enterprise-grade solution and requires server-side setup by your organization. It is not available for personal or private use.

FAQs

1. Can I use Threema OnPrem as a private user?

No, Threema OnPrem is specifically designed for organizations and enterprises. It requires self-hosting on a company-owned server and is not available for individual or personal use.

2. How secure is communication within Threema OnPrem?

Threema OnPrem offers end-to-end encryption for all messages, calls, and shared files. It operates in a completely closed environment without any connection to external networks, ensuring full control and confidentiality.

3. What kind of system setup is required to run Threema OnPrem?

Your organization must host Threema OnPrem on its own servers. This allows seamless integration into existing IT and security infrastructures, and ensures that all data remains in-house.

4. Does Threema OnPrem support voice and video calling?

Yes. Users can make secure one-on-one or group voice and video calls, all protected with end-to-end encryption. Calls can be made without revealing phone numbers.

5. Can I manage users and permissions centrally?

Yes, Threema OnPrem includes a powerful admin portal where you can manage users, control permissions, configure security settings, monitor usage statistics, and support BYOD policies.

Version History

v6.1.1o—17 Jul, 2025

- Fixed a possible crash that occurred when opening the archive

- Fixed a bug that could occur when selecting text in messages

- Fixed a bug that could occur when creating a backup

v5.8.2o—10 Apr, 2025

- Emoji reactions are now included in the data backup

- Fixed a bug that caused custom ringtones to be reset when starting the app

v5.8.1o—27 Feb, 2025

- New: You can now react to messages with emoji

- Fixed a bug concerning profile pictures in group calls