Privacy that fits in your pocket

Use anything by Open Whisper Systems.

Edward Snowden, Whistleblower and privacy advocate

Signal is the most scalable encryption tool we have. It is free and peer reviewed. I encourage people to use it everyday.

Laura Poitras, Oscar winning filmmaker and journalist

I am regularly impressed with the thought and care put into both the security and the usability of this app. It's my first choice for an encrypted conversation.

Bruce Schneier, internationally renowned security technologist

After reading the code, I literally discovered a line of drool running down my face. It’s really nice.

Matt Green, Cryptographer, Johns Hopkins University

Private messaging

For iPhone and Android

  • Say Anything - Send high-quality group, text, picture, and video messages, all without SMS and MMS fees.
  • Be Yourself - Use your existing phone number and address book. There are no separate logins, usernames, passwords, or PINs to manage or lose.
  • Stay Private - We cannot read your messages, and no one else can either. Everything is always end-to-end encrypted and painstakingly engineered in order to keep your communication safe.
  • Get Organized - Archive functionality makes it easy to keep track of the conversations that matter to you right now.
  • Pay Nothing - The development team is supported by community donations and grants. There are no advertisements, and it doesn't cost anything to use.
iPhone app on App Store Android app on Google Play

Private calling

For iPhone and Android

  • Speak Freely - Make crystal-clear phone calls to people who live across town, or across the ocean, with no long-distance charges.
  • Stay Private - We cannot hear your conversations, and no one else can either. No exceptions.
  • Pay Nothing - The development team is supported by community donations and grants. There are no advertisements, and it doesn't cost anything to use.
iPhone app on App Store Android app on Google Play

The Open Whisper Systems Team

Making private communication simple.

Moxie Marlinspike

Moxie works on the protocols, the Android clients, and the server software. He has been contributing to Open Whisper Systems since it was Whisper Systems, formerly ran the product security team at Twitter, started the first cloud-based password cracking service, and has published a number of attacks on secure protocols like SSL and MS-CHAPv2.

Tyler Reinhard

Tyler oversees brand development and design, and works directly on Signal for iOS and the browser. If he's not complaining about the weather, he's usually advocating on behalf of our users. He is also the founder of Mask Magazine, a youth culture + style magazine.

Lilia Kai

Lilia develops the browser extension and maintains the website. She comes to Open Whisper Systems from the EFF, where she built online advocacy tools for activists fighting for a better internet. In her spare time she practices yoyo tricks and DIY home automation. She also serves as chief of sticker operations.

Riya Abraham

Riya supports you, the user, and is also a cheerleader for your feature requests. She used to run automated strategies in the derivatives trading world, and currently moonlights as a Hatha & Vinyasa yoga teacher.

Michael Kirk

Michael works on the iOS client. He is a startup escapee, educator, and mapping enthusiast. When he occasionally stops staring at his computer, you'll find him fixing bikes or running around in the woods.

Open Whisper Systems is both a large community of volunteer Open Source contributors, as well as a small team of dedicated grant-funded developers. Together, we're working to advance the state of the art for secure communication, while simultaneously making it easy for everyone to use.