Slack is a channel-based messaging platform that has become the standard for workplace communication, replacing email as the primary tool for team collaboration in technology companies and beyond. It solves the problem of scattered, slow, and siloed workplace communication by providing organized channels for topics, projects, and teams, combined with direct messaging, file sharing, and integrations that bring work tools into a single conversational interface. Slack fundamentally changed how teams communicate by making conversations searchable, transparent, and contextually organized.
Slack features organized channels with threading for focused discussions, direct messages and group DMs, voice and video calls with huddles for quick conversations, file sharing with previews, a powerful search engine for finding messages and files, and Slack Connect for communicating with external organizations. Its Workflow Builder enables no-code automation of routine processes, and Slack canvas provides a persistent surface for pinning important information. Slack also supports rich message formatting, custom emoji, app integrations through the Block Kit framework, and enterprise features including data loss prevention, compliance exports, and SAML SSO.
Slack is used by millions of organizations worldwide, from two-person startups to Fortune 500 companies, as the central hub for team communication and collaboration. It is particularly dominant among technology companies, where its extensive integration ecosystem connects with virtually every development, design, and business tool. Slack integrates with over 2,600 apps including GitHub, Jira, Google Workspace, Salesforce, Zoom, and Figma, and provides a comprehensive API and SDK for building custom bots, slash commands, and interactive workflows.