Siilo Messenger.

The free secure messaging app for medical team players

Instantly message your colleagues, or healthcare professionals outside of your department or organisation, discussing the same patient as you are. Whether it’s plain text, pictures, audio, video, or a large file that you want to share: Siilo makes it happen, 100% secure and confidential.

Users experience Siilo as a professional networking booster as well

Create a compelling profile page to show your medical skills. Through the app’s network menu tab, you can easily find people in your organisation who are not in your contact list (yet). And if your profile is verified: feel free to search Siilo’s verified user base to find people or specialists outside of your current network. As the famous poet John Donne wrote: “No man is an island”. So let’s start practicing medicine together.



  • Sending, sent and read receipts
  • Send photos, videos, audio recordings, PDF’s
  • Copy, forward and delete messages
  • Create groups with up to 300 colleagues
  • Mute noisy groups
  • @mention another user
  • Seamlessly invite colleagues into groups through email or QR code scanning
  • Save individual chats (to avoid automatic deletion after 30 days)
  • Easily separate general chat from case-related discussions
  • Simply export PDFs of case discussions
  • Blur tool to anonymise patient information
  • Arrow tool to point out important aspects of a picture or scan
  • Automatic looping of videos
  • Secure 1-on-1 audio and video calling
  • Coming soon: medical emojis (a.k.a. medimojis)

Desktop messaging:

  • In-sync web messenger tool provided (login at top menu of this site)
  • Import/export files directly from the PC that is running your EHR
  • Out-of-office reply

Professional networking:

  • Professional medical profile page
  • Connect with colleagues via invitation (email, SMS, WhatsApp) or by QR code scanning
  • Contact discovery based on contact list of your phone
  • Organisation directory on network tab (for organisations subscribed to Siilo Connect)
  • User verification: only registered healthcare professionals get verified
  • Profile verification status visible on avatars
  • Network functionalities on network tab (for verified members only)
  • Create searchable group chats (for verified members only)

File transfer and archiving:

  • End-to-end encrypted file transfer (any type) up to 500 MB (soon 2 GB)
  • Use 3D touch (iOS) or the dedicated Siilo camera app (Android) to take photos and videos to keep them out of your personal library
  • Import photos and videos directly in the secure Siilo Archive from your personal library

Security and compliance:

  • Proven, open source end-to-end encryption of data in transit (NaCl Networking and Cryptography Library)
  • End-user and processor agreement
  • ISO-27001 certification
  • Transport layer security (TLS 1.2), certificate pinning
  • Encryption of data at rest. Decryption only possible with correct pin code, or Touch- or Face ID
  • Mandatory secure login by pin code, Touch-ID, or Face-ID
  • Use 3D touch to take photos and videos to keep them out of your personal library
  • Users are verified and a user’s verification status is visible on the avatar
  • Messages are not displayed in push notifications by default
  • Messages are deleted after 30 days by default
  • Remote wipe of app database is possible
  • Blur tool to remove patient identifiers on photos

Realtime statistics.

Used in countries (this shift number only)

Last installation

A physician from on at 9:37 am

Why is the Siilo app free?

We simply want you to be able to collaborate better through our messaging app. Monetizing on you as an individual healthcare professional would seriously hinder this. That’s why we’ve decided to focus our business model on helping healthcare organisations to comply with data protection regulations. Siilo Connect is our subscription service for organisations or professional associations, providing them with extensive management-, administration-, networking- and software integration tools.