Slack Alternatives for Online

Hangouts is an instant messaging software developed by Google.

Discord is a freeware proprietary VoIP application designed for gaming communities.

Jitsi (formerly SIP Communicator) is a free and open source multiplatform voice (VoIP), videoconferencing and instant messaging application.

Basecamp is a project management web app.

Glip is fully searchable, real-time group chat; video chat, task management, file sharing app.

An alternative to Slack with similar functionality.

Wire is a cross-platform, encrypted instant messaging client created by Wire Swiss. It is available for iOS, Android, Linux, Windows, macOS and Web browser clients.

eXo Platform is an open source, standard-based, Enterprise Social Collaboration Platform.

Matrix is an open protocol for real-time communication. It is designed to allow users with accounts at one communications service provider to communicate with users of a different service provider via online chat, Voice over IP, and Videotelephony.

Whaller allows teams and organizations to create their own internal social networks, meaning no adverts and no data exploitation.

Hibox provides task management, business chat and video calls.

TribeScale is an All-in-One platform to coordinate your team around what really matters - communication, goals, decisions, tasks and results.

Yammer is a freemium enterprise social networking service used for private communication within organizations.

Flock is a communication app for teams. Packed with tons of productivity features, Flock drives efficiency and boosts speed of execution.

Grape is an REST-like API framework for Ruby. It's designed to run on Rack or complement existing web application frameworks such as Rails and Sinatra by providing a simple DSL to easily develop RESTful APIs.

Fleep enables communication within and across organizations, be it your team chats, project communication or 1:1 conversations.

Jostle is a people engagement platform mainly focused on employee engagement.

Zulip is a chat and collaborative software.

kune is a distributed social network software.

Flowdock is a group chat for teams which integrates with GitHub, Jira, Trello.

Dialog Messenger is a handy and feature-rich enterprise multi-device messenger available for server or cloud.

Gitter is an open source instant messaging and chat room system for developers and users of GitHub repositories.

Hack Chat is a minimal, distraction-free chat application.

Hubgets provides chat, voice and video turning team communication.

Stackfield provides end-to-end encrypted communication and collaboration with tasks, documents and projects for business teams.