Browser-based app for easy to use, accessible encrypted chat.
Cryptocat is an experimental browser-based chat client for easy to use, encrypted conversations. It aims to make encrypted, private chat easy to use and accessible. We want to break down the barrier that prevents the general public from having an accessible privacy alternative that they already know how to use. Cryptocat is currently available for Chrome, Firefox and Safari. It uses the OTR protocol over XMPP for encrypted two-party chat and the (upcoming) mpOTR protocol for encrypted multi-party chat.
Git repository branches are in-development, nightly builds! They may not work at all. For stable usable builds, check the releases section.
Cryptocat is still under development. Only use it for experimentation! We've had quite a few serious bugs in the past couple of years. Reports are available on our blog.
make chrome to build a Google Chrome-loadable .zip extension (or just .zip the directory.)
Also available from the Chrome Web Store.
make firefox to build a Mozilla Firefox-loadable .xpi extension (or just .zip the directory and change the extension to .xpi.)
Also available from Mozilla Firefox Addons.
make opera to build an Opera-compatible .nex extension (or just .zip the directory and change the extension to .nex)
Also available from Opera Addons.
Apple's model makes an automated build process difficult.
Also available from Cryptocat.
Apple Mac OS X
make mac to build as a standalone Mac application. (After running
make mac, you can also
open src/mac/Cryptocat.xcodeproj to edit & build the project in Xcode normally.) Building the Mac version requires HomeBrew to be installed to fetch a Tor dependency on
Also available from the Mac App Store.
- XMPP [DONE] | Discussion, Library
- OTR [DONE] | Discussion, Library
- mpOTR | Discussion, Spec in progress. Currently relying on the Cryptocat Multiparty Protocol
CONTRIBUTING.md for guidelines on how to contribute.
SECURITY.md for guidelines on reporting security issues.
Documentation & Wiki
- Multiparty Protocol Specification
- OTR Encrypted File Transfer Specification
- Server Deployment Instructions
- Threat Model
- Design and Functionality Overview
- Architecture and Lifecycle
Discussion & Blog
Builds for all platforms are available for download from GitHub Releases, in addition to the sources above. Please be mindful that GitHub builds do not auto-update.
CHANGELOG.md for an account of the changes made with each version update.
Cryptocat is released under the GNU Affero General Public License (AGPL3).
The full license text is included in