What is Slack Presence?

Understanding Slack Presence

When you're actively using Slack — typing, clicking, or scrolling — your presence shows as a solid green dot (active). When Slack detects inactivity for roughly 10 minutes, or when all your connected devices disconnect, it switches to a hollow circle (away). Unlike your custom status (the emoji and text you can set manually), presence is automatic and can't be directly controlled through Slack settings. Slack determines presence using WebSocket connections between your device and Slack's servers. Each connected client (desktop app, mobile app, browser tab) maintains its own persistent WebSocket connection, and the server tracks the last activity timestamp from each one independently. When evaluating your presence, Slack checks across all connected clients: if any single client has reported recent activity, you appear active everywhere. When all clients go silent, Slack's server-side timer starts counting down from the most recent signal. The approximately 10-minute threshold has remained consistent since Slack introduced automatic presence, though the exact implementation details aren't publicly documented. Multi-device behavior is one of the most misunderstood aspects of Slack presence. Your presence status is account-wide, not device-specific. If you're scrolling through Slack on your phone while your desktop app sits idle, your status shows as active on both devices — teammates see one unified green dot, not separate per-device indicators. Conversely, if your phone app gets backgrounded by iOS and your desktop is idle, both devices contribute to the 'all clients silent' state, and away triggers. This aggregation means that having Slack installed on multiple devices generally helps maintain presence, since any interaction on any device resets the timer for your entire account. The desktop and mobile clients differ in how aggressively they report activity. The desktop app (Mac, Windows, Linux) maintains a stable WebSocket connection as long as the app is running and the computer is awake. It sends activity heartbeats whenever it detects keyboard or mouse input in the Slack window. The mobile app, by contrast, is subject to operating system restrictions: iOS and Android suspend background apps to save battery, which disconnects the WebSocket within minutes of switching away from Slack. The browser client falls somewhere in between — Chrome and Firefox deprioritize background tabs, which can slow or stop heartbeats even though the tab is technically still open. For remote workers, this creates a fundamental challenge: your actual availability during work hours doesn't always match the activity signals Slack requires. Reading documents, attending video calls, or reviewing code in another application produces no Slack interaction, causing the green dot to disappear even though you're actively working. This disconnect between real availability and perceived availability is why presence management tools exist.